Miscellany

Jai Ganesh · 2025-08-27 19:19:38

2376) Shinkansen

Gist

The Shinkansen, or "Bullet Train," is Japan's high-speed railway network, known for its speed, reliability, and advanced technology. Opened in 1964 to connect distant regions and facilitate economic growth, the Shinkansen network allows passengers to travel efficiently between major cities like Tokyo, Osaka, and Fukuoka. The trains are characterized by their aerodynamic, bullet-shaped noses and operate on dedicated tracks, with a central management system ensuring high levels of safety.

Summary

The Shinkansen, colloquially known in English as the bullet train, is a network of high-speed railway lines in Japan. It was initially built to connect distant Japanese regions with Tokyo, the capital, to aid economic growth and development. Beyond long-distance travel, some sections around the largest metropolitan areas are used as a commuter rail network. It is owned by the Japan Railway Construction, Transport and Technology Agency and operated by five Japan Railways Group companies.

Starting with the Tokaido Shinkansen (515.4 km; 320.3 mi) in 1964, the network has expanded to consist of 2,951.3 km (1,833.9 mi) of lines with maximum speeds of 260–320 km/h (160–200 mph), 283.5 km (176.2 mi) of Mini-shinkansen lines with a maximum speed of 130 km/h (80 mph), and 10.3 km (6.4 mi) of spur lines with Shinkansen services. The network links most major cities on the islands of Honshu and Kyushu, and connects to Hakodate on the northern island of Hokkaido. An extension to Sapporo is under construction and was initially scheduled to open by fiscal year 2030, but in December 2024, it was delayed until the end of FY2038. The maximum operating speed is 320 km/h (200 mph) (on a 387.5 km (241 mi) section of the Tōhoku Shinkansen). Test runs have reached 443 km/h (275 mph) for conventional rail in 1996, and up to a world record 603 km/h (375 mph) for SCMaglev trains in April 2015.

The original Tokaido Shinkansen, connecting Tokyo, Nagoya, and Osaka —three of Japan's largest cities — is one of the world's busiest high-speed rail lines. In the one-year period preceding March 2017, it carried 159 million passengers, and since its opening more than six decades ago, it has transported more than 6.4 billion total passengers. At peak times, the line carries up to 16 trains per hour in each direction with 16 cars each (1,323-seat capacity and occasionally additional standing passengers) with a minimum headway of three minutes between trains.

The Shinkansen network of Japan had the highest annual passenger ridership (a maximum of 353 million in 2007) of any high-speed rail network until 2011, when the Chinese high-speed railway network surpassed it at 370 million passengers annually.

Details

Shinkansen, pioneer high-speed passenger rail system of Japan, with lines on the islands of Honshu, Kyushu, and Hokkaido. It was originally built and operated by the government-owned Japanese National Railways and has been part of the private Japan Railways Group since 1987.

The first section of the original line, a 320-mile (515-km) stretch between Tokyo and Ōsaka, was opened in 1964. Known as the New Tōkaidō Line, it generally follows and is named for the historic and celebrated Tōkaidō (“Eastern Sea Road”) highway that was used especially during the Edo (Tokugawa) period (1603–1867). Inauguration of the line, just before the start of the Tokyo 1964 Olympic Games, was greeted by widespread international acclaim, and the Shinkansen was quickly dubbed the “bullet train” for the great speed the trains obtained and for the aerodynamic bullet shape of their noses. Many innovations, such as the use of prestressed concrete ties and mile-long welded sections of track, were introduced in the line’s construction. A 100-mile (160-km) extension of that line westward from Ōsaka to Okayama was completed in 1972, and its final segment, a 244-mile (393-km) stretch between Okayama and the Hakata station in Fukuoka, northern Kyushu, opened in 1975.

Other lines radiating northward from Tokyo were completed in 1982 to the cities of Niigata (the Jōetsu line) and Morioka (the Tōhoku line), the Tōhoku line subsequently being extended northward to Hachinohe in 2002. Work to build a link to Aomori, northwest of Hachinohe, began in the late 1990s. When that segment opened in 2010, the Shinkansen was essentially complete for the entire length of Honshu. However, plans had long been in place to connect all three main Japanese islands by Shinkansen with a line northward into Hokkaido (via the Seikan Tunnel under Tsugaru Strait). Construction on the Hokkaido line began in 2005 on the segment between Aomori and Hakodate in southern Hokkaido, the ultimate goal being to extend the line to Sapporo. The line between Aomori and Hakodate opened in 2016. Construction on the section from Hakodate to Sapporo was begun in 2012 and expected to be completed in 2031.

Branches from the Tōhoku line to Yamagata opened in 1992 (extended north to Shinjo in 1999) and to Akita in 1997; a branch from the Jōetsu line to Nagano also opened in 1997. Segments of a further extension of the Nagano branch westward to Toyama and Kanazawa opened in 2015. In addition, a line was completed between Yatsushiro and Kagoshima in southwestern Kyushu in 2004. In the late 1990s work commenced to extend that line northward from Yatsushiro to Hakata, and the opening of the segment in 2011 completed the full north-south route of the Shinkansen on Kyushu. Work began in 2008 on a branch from the Kyushu line southwestward to Nagasaki, and it opened in 2022.

Much of the system’s track runs through tunnels, including one under Shimonoseki Strait between Honshu and Kyushu, another on the Tokyo-Niigata line that is 14 miles (23 km) long, and another near Aomori with a record length (for a double-tracked inland tunnel) of 16.5 miles (26.5 km) when the bore was finished in 2005. Several hundred trains operate daily on the Shinkansen system. The most-frequent service is between Tokyo and Ōsaka, especially during the morning and evening rush hours, when trains depart at intervals of 10 minutes or less. The fastest trains can make the trip from Tokyo to Hakata in about five hours, and the quickest from Tokyo to Aomori take about three hours.

The electric multiple-unit trains, which can seat 1,000 passengers or more, derive their power from an overhead wire system. Trains originally reached top speeds of 130 miles (210 km) per hour, but improvements in track, train cars, and other components have made possible maximum speeds of between 150 and 185 miles (240 and 300 km) per hour. In early 2013 some trains began operating at up to 200 miles (320 km) per hour. Such high speeds made it necessary to develop elaborate safety features. Each car, for example, is equipped with brakes consisting of cast-iron discs and metallic pad linings specially designed not to distort under emergency braking. Moreover, all movements of the trains are monitored and controlled by a central computerized facility in Tokyo.

Additional Information

Japan's main islands of Honshu, Kyushu and Hokkaido are served by a network of high speed train lines that connect Tokyo with most of the country's major cities. Japan's high speed trains (bullet trains) are called shinkansen and are operated by Japan Railways (JR).

Running at speeds of up to 320 km/h, the shinkansen is known for punctuality (most trains depart on time to the second), comfort (relatively silent cars with spacious, always forward-facing seats), safety (no fatal accidents in its history) and efficiency. Thanks to various rail passes, the shinkansen can also be a cost-effective means of travel.

Shinkansen network

The shinkansen network consists of multiple lines, among which the Tokaido Shinkansen (Tokyo - Nagoya - Kyoto - Osaka) is the oldest and most popular. All shinkansen lines (except the Akita and Yamagata Shinkansen) run on tracks that are exclusively built for and used by shinkansen trains. Most lines are served by multiple train categories, ranging from the fastest category that stops only at major stations to the slowest category that stops at every station.

Jai Ganesh · 2025-08-28 17:59:13

2377) Chimpanzee

Gist

Chimpanzees are highly intelligent primates, demonstrating problem-solving skills, tool use, complex communication, and social intelligence. They can learn to use symbols, understand basic commands, and even display empathy and cultural behaviors. While their brains are smaller than humans, they exhibit remarkable cognitive abilities within their own context.

While chimpanzees can form affectionate bonds and exhibit friendly behavior, their unpredictability means that they can also be dangerous. Their wild instincts, intelligence, and emotional depth make them fascinating, but they also deserve respect. Chimpanzee are not pets and should not be treated as such.

Summary

The chimpanzee, also simply known as the chimp, is a species of great ape native to the forests and savannahs of tropical Africa. It has four confirmed subspecies and a fifth proposed one. When its close relative the bonobo was more commonly known as the pygmy chimpanzee, this species was often called the common chimpanzee or the robust chimpanzee. The chimpanzee and the bonobo are the only species in the genus Pan. Evidence from fossils and DNA sequencing shows that Pan is a sister taxon to the human lineage and is thus humans' closest living relative.

The chimpanzee is covered in coarse black hair but has a bare face, fingers, toes, palms of the hands, and soles of the feet. It is larger and more robust than the bonobo, weighing 40–70 kg (88–154 lb) for males and 27–50 kg (60–110 lb) for females and standing 150 cm (4 ft 11 in).

The chimpanzee lives in groups that range in size from 15 to 150 members, although individuals travel and forage in much smaller groups during the day. The species lives in a strict male-dominated hierarchy, where disputes are generally settled without the need for violence. Nearly all chimpanzee populations have been recorded using tools, modifying sticks, rocks, grass and leaves and using them for hunting and acquiring honey, termites, ants, nuts and water. The species has also been found creating sharpened sticks to spear small mammals. Its gestation period is eight months. The infant is weaned at about three years old but usually maintains a close relationship with its mother for several years more.

The chimpanzee is listed on the IUCN Red List as an endangered species. Between 170,000 and 300,000 individuals are estimated across its range. The biggest threats to the chimpanzee are habitat loss, poaching, and disease. Chimpanzees appear in Western popular culture as stereotyped clown-figures and have featured in entertainments such as chimpanzees' tea parties, circus acts and stage shows. Although chimpanzees have been kept as pets, their strength, aggressiveness, and unpredictability makes them dangerous in this role. Some hundreds have been kept in laboratories for research, especially in the United States. Many attempts have been made to teach languages such as American Sign Language to chimpanzees, with limited success.

Details

A chimpanzee, (Pan troglodytes), is a species of ape that, along with the bonobo, is most closely related to humans. Chimpanzees inhabit tropical forests and savannas of equatorial Africa from Senegal in the west to Lake Albert and northwestern Tanzania in the east. Individuals vary considerably in size and appearance, but chimpanzees stand approximately 1–1.7 metres (3–5.5 feet) tall when erect and weigh about 32–60 kg (70–130 pounds). Males tend to be larger and more robust than females. Chimpanzees are covered by a coat of brown or black hair, but their faces are bare except for a short white beard. Skin colour is generally white except for the face, hands, and feet, which are black. The faces of younger animals may be pinkish or whitish. Among older males and females, the forehead often becomes bald and the back becomes gray.

Natural history

Chimpanzees awaken at dawn, and their day is spent both in the trees and on the ground. After a lengthy midday rest, late afternoon is usually the most intensive feeding period. In the trees, where most feeding takes place, chimps use their hands and feet to move about. They also leap and swing by their arms (brachiate) skillfully from branch to branch. Movement over any significant distance usually takes place on the ground. Though able to walk upright, chimpanzees more often move about on all fours, leaning forward on the knuckles of their hands (knuckle walking). At night they usually sleep in the trees in nests they build of branches and leaves. Chimpanzees are unable to swim, but they will wade in water. The chimpanzee diet is primarily vegetarian and consists of more than 300 different items, mostly fruits, berries, leaves, blossoms, and seeds but also bird eggs and chicks, many insects, and occasionally carrion. Chimpanzees also hunt, both alone and in groups, stalking and killing various mammals such as monkeys, duikers, bushbucks, and wild pigs. They also appear to use certain plants medicinally to cure diseases and expel intestinal parasites.

The female chimpanzee bears a single young at any time of year after a gestation period of about eight months. The newborn weighs about 1.8 kg (about 4 pounds), is almost helpless, and clings to the fur of the mother’s belly as she moves. From about 6 months to 2 years, the youngster rides on the mother’s back. Weaning takes place at about 5 years. Males are considered adults at 16 years of age, and females usually begin to reproduce at about 13 years, but often only two offspring survive during her lifetime. The longevity of chimps is about 45 years in the wild and 58 in captivity; however, older individuals have been documented. For example, Cheetah the chimpanzee, an animal actor from the Tarzan movies of the 1930s and ’40s, was reported to have lived approximately 80 years.

Conservation status

Chimpanzees are an endangered species; their population in the wild has been reduced by hunting (primarily for meat), destruction of habitat from logging or farming, and commercial exportation for use in zoos and research laboratories. The International Union for Conservation of Nature (IUCN) noted that, despite having one of the largest geographic ranges of the great apes, chimpanzee populations have fallen significantly since the 1980s. Lions and leopards also prey upon chimpanzees.

Social behaviour

Chimpanzees are lively animals with more extraverted dispositions than either gorillas or orangutans. They are highly social and live in loose and flexible groups known as communities, or unit groups, that are based on associations between adult males within a home range, or territory. Home ranges of forest-dwelling communities can be as small as a few square kilometres, but home ranges covering hundreds of square kilometres are known among savanna communities. A community can number from 20 or fewer to well over 100 members. Each consists of several subgroups of varying size and unstable composition. Social dominance exists, with adult males being dominant over adult females and adolescent males. Within a community, there are twice or three times as many adult females as adult males; the number of adults is about equal to the number of immature individuals. Communities usually divide into subgroups called parties, which vary widely in size. The dominance hierarchy among male chimpanzees is very fluid; individuals associate with each other and join and leave different subgroups with complete freedom. The dominant (alpha) male of a group can monopolize ovulating females through possessive behaviour. On the other hand, gang attack by subordinate males can expel an alpha male. Males spend all of their lives in the community they are born in, but occasionally a juvenile male may transfer to another community with his mother. In contrast to males, most females leave their group of birth to join a neighbouring group when they mature at around age 11. Female chimpanzees spend most of their time with their young or with other females. Those with dependent offspring are more likely to range alone or in small parties within narrow “core areas.” Females have been known to form coalitions against a bullying adult male or newly immigrated female.

Relations between different chimp communities tend to be hostile. Intruders on a group’s home range may be attacked, and adult males engage in boundary patrol. On rare occasions, a group may invade a neighbouring territory that is much smaller in size, and fatalities among the smaller group result. Infanticide and cannibalism by adult males, and to a lesser extent by adult females, have been observed. Victimized infants are not only those of neighbouring groups but also those born to newly immigrated females. Between- and within-group competition among individuals of the same gender is the likely cause of such violence. Sometimes a male and female will form a consortship, engaging in exclusive mating relationships by leaving other members of the group and staying in the periphery of the group range. This strategy, however, brings increased risk of attack by neighbouring groups.

Chimpanzees exhibit complex social strategies such as cooperation in combat and the cultivation of coalitions and alliances via ranging together, reciprocal grooming, and the sharing of meat (sometimes in exchange for mating opportunities). An alpha male, for instance, may interfere with his rival in grooming with a third party because such a coalition might jeopardize the alpha’s status. On the other hand, the third party might show strategic opportunism in such a situation, since his assistance to either side could determine which of his superiors prevails. Chimpanzees, therefore, appear to have some concept of “trade.” They console, reconcile, and retaliate during fighting and so share emotions and aspects of psychology similar to those found in humans: self-recognition, curiosity, sympathy, grief, and attribution. Although chimps take care of orphaned infants, they also tease handicapped individuals, conceal information that would bring disadvantage to themselves, and manipulate others for their own advantage by expressing deceptive postures, gestures, and facial expressions.

Intelligence

Chimpanzees are highly intelligent and are able to solve many kinds of problems posed to them by human trainers and experimenters. A number of researchers have taught chimpanzees to use sign language or languages based on the display of tokens or pictorial symbols. The implications of these language studies have been contested, however. Critics charge that apes have not acquired true language in the sense of understanding “words” as abstract symbols that can be combined in meaningful new ways. Other investigators maintain that more recent language training has resulted in the chimpanzees’ acquiring a true recognition of “words” as abstractions that can be applied in novel contexts.

Communication between chimps in the wild takes the form of facial expressions, gestures, and a large array of vocalizations, including screams, hoots, grunts, and roars. Males display excitement by standing erect, stamping or swaying, and letting out a chorus of screams. Chimps use louder calls and gestures for long-distance communication (such as drumming on tree buttresses) and quieter calls and facial expressions for short-distance communication. Similarities to human laughter and smiling might be seen in their “play panting” and grinning, respectively.

Various tools are used in several contexts. Chimpanzees “fish” for termites and ants with probes made of grass stalks, vines, branches, peeled bark, and midribs of leaves. They crack hard nuts open by using stones, roots, and wood as hammers or anvils, and they use “leafy sponges” (a handful of folded leaves or moss) to drink water. Branches and leaves are detached and displayed during courtship. In threat displays, chimps throw rocks and drag and throw branches. Sticks are used to inspect dead pythons or other unfamiliar objects that might be dangerous. Leaves are used hygienically in wiping the mouth or other soiled body parts. Chimpanzees also use different tools in succession as a “tool set.” For example, chimpanzees of the Congo basin first dig into termite mounds with a stout stick and then fish for individual termites with a long, slender wand. Tools are also used in combination as “tool composites.” Chimpanzees in the Guinea region push leafy sponges into hollows of trees containing water and then withdraw the wet sponges by using sticks. Chimps thus differ locally in their repertoire of tool use, with younger animals acquiring tool-using behaviours from their elders. Such cultural differences are also seen in food items consumed and in gestural communication. Chimpanzees indeed possess culture when it is defined as the transmission of information from generation to generation via social learning shared by most members of a single age or gender class in a given group.

Chimpanzees’ intelligence, responsiveness, and exuberance have made them ideal nonhuman subjects for psychological, medical, and biological experiments. Young chimpanzees can become very attached to their human trainers, and their expressions of feeling resemble those of humans more closely than any other animal.

Taxonomy

Genetic analysis suggests that the lineages leading to modern humans and chimpanzees diverged from each other between 6.5 million and 9.3 million years ago and that at least 98 percent of the human and chimpanzee genomes are identical. Chimpanzees are classified taxonomically as a single species, Pan troglodytes. (The so-called pygmy chimpanzee, or bonobo, is a distinct and separate species, P. paniscus, that diverged from chimpanzees about 1.7 million years ago.) Four subspecies of P. troglodytes are recognized: the tschego, or Central African chimpanzee (P. troglodytes troglodytes), also known as the common chimpanzee in continental Europe; the West African, or masked, chimpanzee (P. troglodytes verus), known as the common chimpanzee in Great Britain; the East African, or long-haired, chimpanzee (P. troglodytes schweinfurthii); and the Nigerian-Cameroon chimpanzee (P. troglodytes ellioti, which was formerly classified as P. troglodytes vellerosus).

Additional Information

Like us, chimps are highly social animals, care for their offspring for years and can live to be over 50. In fact, chimpanzees are our closest cousins; we share about 98% of our genes.

In their habitat in the forests of Central Africa, chimpanzees spend most of their days in the treetops. When they do come down to earth, chimps usually travel on all fours, though they can walk on their legs like humans for as far as a mile. They use sticks to fish termites out of mounds and bunches of leaves to sop up drinking water.

050825_jb_chimp-chatter_feat.jpg?resize=1380%2C776&ssl=1

Jai Ganesh · 2025-09-02 20:18:55

2378) Rafflesia arnoldii

Gist

Often called the corpse flower, Rafflesia arnoldi blooms into the single largest individual flower in the world. When it does, it emits a vile aroma, similar to rotten meat, attracting insects, such as flies and beetles, that feed on dead flesh.

Summary

Rafflesia is (genus Rafflesia), genus of about 42 species of parasitic plants native to Southeast Asia. All Rafflesia species parasitize the roots of Tetrastigma vines (family Vitaceae), and their presence is not made known until the striking flowers emerge from the host vine. One species, Rafflesia arnoldii, boasts the largest single flower of any plant.

Taxonomy

Kingdom: Plantae
Clade: Angiosperm
Order: Malpighiales
Family: Rafflesiaceae
Genus: Rafflesia

Physical description

Like other members of the family Rafflesiaceae, Rafflesia plants are endoparasitic, meaning that the vegetative organs are so reduced and modified that the plant body exists only as a network of threadlike cellular strands living almost wholly within the tissues of the host plant. There are no green photosynthetic tissues, leaves, roots, or stems in the generally accepted sense, although vestiges of leaves exist in some species as scales. Rafflesia plants are thus obligate parasites, which cannot live without the nutrition provided by the host. Despite the dramatic reduction of most of the plant body, the flowers are well developed and can be extremely large.

Rafflesia flowers are sturdy, typically with five substantial tepals (undifferentiated petals and sepals) surrounding the gender organs in a central cup. Interestingly, individual flowers are unisexual, meaning that pollination can occur only if another flower of the opposite gender is simultaneously blooming. The distinctive flowers are sapromyiophilous, meaning that they are pollinated by carrion-feeding flies, and they have a number of adaptations to attract their unconventional pollinators. Most are reddish or purplish brown and have a mottled pattern that resembles rotting flesh. In addition, they emit a fetid carrion odor during the few days they are blooming, and some species even generate heat to simulate decomposition. The unusual pollen is transferred by means of a sticky liquid that dries on the flies. The resultant fruit is a berry containing sticky seeds thought to be disseminated by fruit-eating rodents.

Major species and conservation

The genus includes the giant R. arnoldii, sometimes known as the corpse flower or monster flower, which produces the largest-known individual flower of any plant species in the world and is found in the forested mountains of Sumatra and Borneo. Its fully developed flower appears aboveground as a thick fleshy five-lobed structure weighing up to 11 kg (24 pounds) and measuring almost one meter (about one yard) across.

Most Rafflesia species are considered rare and, given their complete dependence on Tetrastigma vines, are extremely difficult to cultivate and very vulnerable to extinction. Major threats include the loss of rainforest habitat, due to logging and other land-use changes, and illegal harvest of the flowers for their purported medicinal properties. As of 2023 only one species, R. magnifica of the Philippines, has been formally evaluated, and it is listed as critically endangered by the IUCN Red List of Threatened Species, though scientists estimate that at least 60 percent of the species are endangered.

Details

Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Eudicots
Clade: Rosids
Order: Malpighiales
Family: Rafflesiaceae
Genus: Rafflesia
Species: R. arnoldii

Binomial name

Rafflesia arnoldii, the corpse flower, or giant padma, is a species of flowering plant in the parasitic genus Rafflesia within the family Rafflesiaceae. It is noted for producing the largest individual flower on Earth. It has a strong and unpleasant odour of decaying flesh. It is native to the rainforests of Sumatra and Borneo. Although there are some plants with larger flowering organs like the titan arum (Amorphophallus titanum) and talipot palm (Corypha umbraculifera), those are technically clusters of many flowers.

Rafflesia arnoldii is one of the three national flowers in Indonesia, the other two being the white jasmine (Jasminum sambac) and moon orchid (Phalaenopsis amabilis). It was officially recognised as a national "rare flower" (Indonesian: puspa langka) in Presidential Decree No. 4 in 1993.

Taxonomy

The first European to find Rafflesia was the ill-fated French explorer Louis Auguste Deschamps. He was a member of a French scientific expedition to Asia and the Pacific, detained by the Dutch for three years on the Indonesian island of Java, where, in 1797, he collected a specimen, which was probably what is now known as R. patma. During the return voyage in 1798, his ship was taken by the British, with whom France was at war, and all his papers and notes were confiscated. Joseph Banks is said to have agitated for the return of the stolen documents, but apparently to no avail; they were lost, turned up for sale around 1860, went to the British Museum of Natural History, where they were promptly lost again. They did not see the light of day until 1954, when they were rediscovered at the Museum. To everyone's surprise, his notes and drawings indicate that he had found and studied the plants long before the British. It is thought quite possible the British purposely hid Deschamps' notes, to claim the 'glory' of 'discovery' for themselves.

In 1818 the British surgeon Joseph Arnold collected a specimen of another Rafflesia species found by a Malay servant in a part of Sumatra, then a British colony called British Bencoolen (now Bengkulu), during an expedition run by the recently appointed Lieutenant-Governor of Bencoolen, Stamford Raffles. Arnold contracted a fever and died soon after the discovery, the preserved material being sent to Banks. Banks passed on the materials, and the honour to study them was given to Robert Brown. The British Museum's resident botanical artist Franz Bauer was commissioned to make illustrations of the new plants. Brown eventually gave a speech before the June 1820 meeting of the Linnean Society of London, where he first introduced the genus and its until then two species. Brown gave the generic name Rafflesia in honour of Raffles. Bauer completed his pictures some time in mid-1821, but the actual article on the subject continued to languish.

William Jack, Arnold's successor in the Sumatran Bencoolen colony, recollected the plant and was the first to officially describe the new species under the name R. titan in 1820. It is thought quite likely that Jack rushed the name to publication because he feared that the French might publish what they knew of the species, and thus rob the British of potential 'glory'. Apparently aware of Jack's work, Brown finally had the article published in the Transactions of the Linnean Society a year later, formally introducing the name R. arnoldii (he ignores Jack's work in his article).

Because Jack's name has priority, R. arnoldii should technically be a synonym of R. titan, but at least in Britain, it was common at the time to recognise the names introduced by well-regarded scientists such as Brown, over what should taxonomically be the correct name. This was pointed out by the Dutch Rafflesia expert Willem Meijer in his monographic addition to the book series Flora Malesiana in 1997. Instead of sinking R. arnoldii into synonymy, however, he declared that the name R. titan was "incompletely known": the plant material used by Jack to describe the plant has been lost.

In 1999, the British botanical historian David Mabberley, in response to Meijer's findings, attempted to rescue Brown's names from synonymy. This is known as 'conservation' in taxonomy, and normally this requires making a formal proposal to the committee of the International Code of Botanical Nomenclature (ICBN). Mabberley thought he found a loophole around such a formal review by noting that while Brown was notoriously slow to get his papers published, he often had a handful of pre-print pages privately printed to exchange with other botanists: one of these pre-prints had been recently bought by the Hortus Botanicus Leiden, and it was dated April 1821. Mabberley thus proposed that this document be considered the official effective publication, stating this would invalidate Jack's earlier name. For some reason Mabberley uses 1821, a few months after Brown's pre-print, as the date of Jack's publication, instead of the 1820 publication date in Singapore. Confusingly, the record in the International Plant Names Index (IPNI) still has yet another date, "1823?", as it was in the Index Kewensis before Meijer's 1997 work. Mabberley's proposals regarding Brown's name were accepted by institutions, such as the Index Kewensis.

Mabberley also pointed out that the genus Rafflesia was thus first validated by an anonymous report on the meeting published in the Annals of Philosophy in September 1820 (the name was technically an unpublished nomen nudum until this publication). Mabberley claimed the author was Samuel Frederick Gray. However, as that is nowhere stated in the Annals, per Article 46.8 of the code of ICBN, Mabberley was wrong to formally ascribe the validation to Gray. The validation of the name was thus attributed to one Thomas Thomson, the editor of the Annals in 1820, by the IPNI. Mabberley admitted his error in 2017. This Thomson was not the botanist Thomas Thomson, who was three years old in 1820, but his identically named father, a chemist, and Rafflesia is thus the only botanical taxon this man ever published.

Errata

An old Kew webpage claimed that Sophia Hull was present when the specimen was collected and finished the colour drawing that Arnold had started of the plant. It also stated that Brown had originally wanted to call the plant genus Arnoldii.

Regional names

It is called kerubut in Sumatra. In the kecamatan ('district') of Pandam Gadang, it is known as cendawan biriang in the Minangkabau language.

Description

Although Rafflesia is a vascular plant, it lacks any observable leaves, stems or even roots, and does not have chlorophyll. It lives as a holoparasite on vines of the genus Tetrastigma, most commonly T. angustifolium. Similar to fungi, individuals grow as a mass of thread-like strands of tissue completely embedded within and in intimate contact with surrounding host cells from which nutrients and water are obtained. It can only be seen outside the host plant when it is ready to reproduce; the only part of Rafflesia that is identifiable as distinctly plant-like are the flowers, though even these are unusual since they attain massive proportions, are reddish-brown with white spots, and stink of rotting flesh. According to Sandved, the flower opens with a hissing sound.

The flower of Rafflesia arnoldii grows to a diameter of around 1 m (3 ft 3 in),[2] and weighs up to 11 kg (24 lb). According to the Mongabay institution, the single largest R. arnoldii to be measured was 1.14 m (3 ft 9 in) in width. These flowers emerge from very large, cabbage-like, maroon or dark brown buds typically about 30 cm (12 in) wide, but the largest (and the largest flower bud ever recorded) found at Mount Sago, Sumatra in May 1956 was 43 cm (17 in) in diameter. Indonesian researchers often refer to the bud as a 'knop' (knob). According to one source, these buds require 21 months to form. Yet the flowers remain open for only four days.

The plant is native to the rainforest regions of Malaysia, Indonesia, the Philippines, and Thailand.

Additional Information

Often called the corpse flower, Rafflesia arnoldi blooms into the single largest individual flower in the world.

When it does, it emits a vile aroma, similar to rotten meat, attracting insects, such as flies and beetles, that feed on dead flesh.

These flesh-loving creatures pollinate the flower, allowing it to spread through the rainforests of Borneo.

Due to the incredibly specific requirements of the plant, almost no botanical gardens have a Rafflesia arnoldi in cultivation, including Kew.

Rafflesia arnoldi has no leaves, stems or roots, and is a parasitic plant that grows on vines in the genus Tetrastigma.

Plant description

Rafflesia arnoldi lives inside Tetrastigma vines as a mass of fleshy strands which absorb water and nutrients from the host. It grows out of the host plant's bark as brown, cabbage-like buds called knops which bloom over several days. The flowers have five lobes, are reddish-brown with white spots, and grow up to 1m across. They appear for a week, releasing a scent of rotting meat.

Cultural

The flower is an iconic symbol of southeast Asian rainforest, and has been depicted on several Indonesian postage stamps.

Fleur-Rafflesia-Borneo-Malaisie-Rafflesia-Flower-Borneo-Malaysia-00002-1536x1154.jpg

Jai Ganesh · 2025-09-03 16:53:36

2379) Bluff (Geography)

Gist

In geography, a bluff is a high, steep slope or cliff that typically overlooks a body of water, formed by the erosion of the outer bank of a river's meander or along a coastline. The term can also refer to a clump of trees, particularly willows or poplars, found on the flat Canadian prairies, which is a different meaning from the geological landform.

Although any cliff with a broad, steep face may be called a bluff, the term bluff refers to a high bank or bold headland with a broad, precipitous, sometimes rounded cliff face. Bluffs can overlook either a plain or a body of water, especially on the outside curve of a stream meander.

Summary

In geography and geology, a cliff or rock face is an area of rock which has a general angle defined by the vertical, or nearly vertical. Cliffs are formed by the processes of weathering and erosion, with the effect of gravity. Cliffs are common on coasts, in mountainous areas, escarpments and along rivers. Cliffs are usually composed of rock that is resistant to weathering and erosion. The sedimentary rocks that are most likely to form cliffs include sandstone, limestone, chalk, and dolomite. Igneous rocks such as granite and basalt also often form cliffs.

An escarpment (or scarp) is a type of cliff formed by the movement of a geologic fault, a landslide, or sometimes by rock slides or falling rocks which change the differential erosion of the rock layers.

Most cliffs have some form of scree slope at their base. In arid areas or under high cliffs, they are generally exposed jumbles of fallen rock. In areas of higher moisture, a soil slope may obscure the talus. Many cliffs also feature tributary waterfalls or rock shelters. Sometimes a cliff peters out at the end of a ridge, with mushroom rocks or other types of rock columns remaining. Coastal erosion may lead to the formation of sea cliffs along a receding coastline.

The British Ordnance Survey distinguishes between cliffs (continuous line along the topper edge with projections down the face) and outcrops (continuous lines along lower edge).

Details:

What Is A Bluff In Geography?

A bluff is a ridge of land that extends into the air. The term is commonly used in geography to refer to high ground. Bluffs are often situated at the foot of steep cliffs and mountains.

A bluff is a steep hill or cliff, especially one that appears close to its base. It can also refer to an area where the slope is so steep that it appears to be an unbroken cliff.

A typical bluff is situated at the foot of steep cliffs and mountains.

Why Is A Bluff Called A Bluff?

A bluff is a cliff, small hill, or other elevation on the side of a mountain or hill, that rises steeply from the ground, usually without trees or shrubs.

Bluffs are called bluff because they appear to be higher than they actually are. From the distance, they seem to be steeper than they actually are.

How Is A Bluff Formed?

How a bluff is formed in geography is a question that has no clear answer. It all depends on the environment that the bluff was formed in and other factors like how deep it is and how much erosion takes place.

When a bluff is created naturally, it forms by the force of wind and water along with the effect of gravity on the earth’s surface. This natural process mainly happens in steep places where there are high elevation changes.

As the slope becomes too steep for the water or wind to erode it, it builds up and forms a bluff.

Bluffs are also formed by the slow movement of glaciers, ice sheets, and permafrost. Glaciers push large amounts of rock off of mountainside through grinding and crushing – this produces large boulders that act as rubble dams blocking the flow of streams.

How To Identify A Bluff In Geography?

Bluffs are natural formations that can be found near water and mountain ranges. They take many forms and typically look like a hill reaching the sky or a mound of rock.

There are many ways to identify a bluff. A bluff is usually steep enough to have a significant decline or incline on both sides of the top.

The bluffs are not just steep but have uneven, sharp sawtooth edges that provide cover for any assailant. The bluff is also made up of large stones that have become cemented together over time and are covered with moss and vegetation, which further provides cover from above.

Bluff is not higher than its surroundings but it grants an advantage to those who use it as cover from above due to the uneven, sharp edges.

Bluffs are also characterized by their lack of vegetation and the presence of large rock formations jutting out from them.

In order to identify a bluff, you need to look at the shape and size. The bluffs should be steep, irregularly shaped.

What Is A Bluff On A Lake Or Beach?

A bluff is a shoreline that plunges abruptly into the water, as seen in some lakes and rivers. In order to prevent erosion from the water, the land behind a bluff is often protected by planting shrubs and trees along the steep slope of the bank.

A bluff can be created naturally or artificially through human efforts such as earth-moving projects, filling of river beds, building dams, or installing rock protections.

Cliff vs Bluff [What Is A Bluff In Geography]

Here are some of the differences between a bluff and a cliff:

Cliff

A cliff is a sharp change in elevation with little or no horizontal level between two points of different elevations. A cliff face is usually vertical or nearly so but can also be almost flat at low elevations.

Such features are typically found in mountainous terrain and may be formed either by erosion or by other types of geological activity.

Cliffs can be considered natural features that stabilize a slope, preventing further erosion and landslides from occurring on the mountainside, but they have also been used for building retaining walls and even as places to live.

Bluff

A bluff is a high point of land that appears to be very steep, but it is actually not.

Bluffs are generally found on the side of a mountain or hill, but sometimes they are found on level ground or even on the seashore.

Bluffs are defined by their steepness, meaning the difference in elevation between the highest point on top of the bluff and its base.

Conclusion: What Is A Bluff In Geography

When you are talking about geography, bluff can be a natural feature, a geological formation, or an archaeological site. These things that are difficult to see from one perspective are easy to spot from another perspective.

Bluff is the name given to a low-lying area of land that is surrounded by steep cliffs, steep slopes, or water. It’s the place you hide in when you don’t want to be seen.

Additional Information

A bluff is a type of broad, rounded cliff. Most bluffs border a river, beach, or other coastal area.

Bluffs may form along a river where it meanders, or curves from side to side. River currents on the outside of the curve erode, or wear away, the lower part of a river bank. No longer supported, the upper part of the bank breaks off, leaving the high wall of a bluff. The 150-meter (500-foot) Great River Bluffs in the U.S. state of Minnesota, for example, were carved by the meanderings of the mighty Mississippi River.

Erosion also produces bluffs along the wider floodplain of a river. Over thousands of years, a meandering river gradually shifts from side to side across its floodplain. Where the meanders, or loops, of the river reach valley walls, the water may carve bluffs. In fact, a “bluff line” defines the outer limits of a river’s floodplain, and is often another name for valley wall. A floodplain’s bluff lines may be steep and narrow, or they may be wide and gentle.

Coastal bluffs are formed through a combination of erosion from wind, sea spray, and crashing waves. These bluffs are often more rugged than their inland counterparts, and are more vulnerable to major erosion. Coastal bluffs, especially those in the Puget Sound region of the U.S. state of Washington, are sometimes called feeder bluffs. The constant erosion of feeder bluffs supplies (feeds) sediment to the beaches and seashore downstream below.

Another sort of coastal bluff is the beach ridge. Beach ridges are formed entirely by waves lapping onshore, pushing sand and sediment up and away from the body of water. Beach ridges run parallel to the shoreline and are often associated with sand dunes. The Indiana Dunes, for example, are extensions of beach ridges formed by the waters of Lake Michigan. At this national lakeshore, tiny bluffs give way to larger dunes, and the ecosystem eventually creates the ideal conditions for an oak forest through the process of plant succession.

Like many types of cliffs, bluffs provide important information about how Earth developed. Scotts Bluff, for instance, rises more than 1,400 meters (4,600 feet) above the North Platte River in the U.S. state of Nebraska. The exposed rock of this national monument allows geologists to peer more than 30 million years into North America’s past. Rock formations at Scotts Bluff preserve the history of ancient volcanic activity nearby, as well as the fossilized presence of prehistoric North American rhinos, tapirs, and even camels.

Life on the Bluff

The summits of many bluffs are bare, rocky outcroppings. However, the harsh environment of bluffs are often vital ecosystems. Tiny organisms called lichen often colonize rocky bluffs, providing vital nutrients for many insects and birds.

Hardy grasses and shrubs can also take root on rocky bluffs. The shallow roots of these plants slow erosion of the bluff, even helping to secure valuable topsoil in some places.

Bluffs provide an ideal nesting spot for fishing birds such as cormorants and kingfishers. Cormorants build their nests on the bare ground of bluffs, bringing sticks and seaweed for construction. Cormorant colonies can grow so large that they take over the entire bluff. Kingfishers don’t nest on top the bluff, but dig a burrow directly in it. They prefer burrows on bluffs with little vegetation, as root systems get in the way of digging.

Bluffs are even home to endangered species. The El Segundo blue butterfly (Euphilotes battoides allyni), for example, is found only in a small bluff ecosystem near the giant Los Angeles International Airport in Southern California.

Jai Ganesh · 2025-09-04 14:33:58

2380) Penguin

Gist

A penguin is a flightless, black-and-white seabird found almost exclusively in the Southern Hemisphere, known for its adaptations to marine life, including flippers for swimming, dense feathers for warmth, and a diet of fish and krill. While most live in cold Antarctic or sub-Antarctic regions, the Galápagos penguin lives near the equator. Penguins are excellent swimmers and divers, using their short, paddle-like wings to propel themselves through the water, and their contrasting dark backs and white bellies provide camouflage.

Penguins primarily live in the Southern Hemisphere, inhabiting cold environments like Antarctica, subantarctic islands, and temperate coasts in countries such as Australia, New Zealand, and South Africa. While most species are found in these southern regions, the Galápagos penguin is an exception, living on islands near the equator in the warm waters off the coast of Ecuador. All penguins require proximity to the ocean for food and to raise their young on land.

Summary

Penguins are a group of aquatic flightless birds from the family Spheniscidae of the order Sphenisciformes. They live almost exclusively in the Southern Hemisphere. Only one species, the Galápagos penguin, is equatorial, with a small portion of its population extending slightly north of the equator (within a quarter degree of latitude). Highly adapted for life in the ocean water, penguins have countershaded dark and white plumage and flippers for swimming. Most penguins feed on krill, fish, squid and other forms of sea life which they catch with their bills and swallow whole while swimming. A penguin has a spiny tongue and powerful jaws to grip slippery prey.

They spend about half of their lives on land and the other half in the sea. The largest living species is the emperor penguin (Aptenodytes forsteri): on average, adults are about 1.1 m (3 ft 7 in) tall and weigh 35 kg (77 lb). The smallest penguin species is the little blue penguin (Eudyptula minor), also known as the fairy penguin, which stands around 30–33 cm (12–13 in) tall and weighs 1.2–1.3 kg (2.6–2.9 lb). Today, larger penguins generally inhabit colder regions, and smaller penguins inhabit regions with temperate or tropical climates. Some prehistoric penguin species were enormous: as tall or heavy as an adult human. There was a great diversity of species in subantarctic regions, and at least one giant species in a region around 2,000 km south of the equator 35 mya, during the Late Eocene, a climate decidedly warmer than today.

Details

A penguin is (order Sphenisciformes), any of 18–21 species of flightless marine birds that live only in the Southern Hemisphere. The majority of species live not in Antarctica but rather between latitudes 45° and 60° S, where they breed on islands. A few penguins inhabit temperate regions, and one, the Galapagos penguin (Spheniscus mendiculus), lives at the Equator.

General features:

The world's deepest-diving birds

The world's deepest-diving birdsEmperor penguins (Aptenodytes forsteri) live in colonies along the coastline of Antarctica. They are capable of diving to depths of about 550 metres (1,800 feet) in search of food, which makes them Earth's deepest-diving birds.

The stocky, short-legged appearance of penguins has endeared them to people worldwide. They range from about 35 cm (14 inches) in height and approximately 1 kg (about 2 pounds) in weight in the blue, or fairy, penguin (Eudyptula minor) to 115 cm (45 inches) and 25 to 40 kg (55 to 90 pounds) in the emperor penguin (Aptenodytes forsteri). Most are black on the back and white below, often with lines of black across the upper breast or spots of white on the head. Colour is rare, being limited to red or yellow irises of the eye in some species; red beaks or feet in a few; yellow brow tufts in the three species of Eudyptes; and orange and yellow on the head, neck, and breast in the emperor and king (A. patagonica) penguins.

The total populations of some species, such as the emperor, are estimated in the hundreds of thousands, but most species of smaller penguins certainly run into the millions. Immense island breeding colonies, some teeming with hundreds of thousands of nesting pairs, represent a large potential food resource, but the economic importance of penguins is negligible. Nineteenth-century whalers and seal hunters visited some colonies for meat and eggs, and a penguin oil industry once took large numbers of the birds. By the early 20th century, however, this exploitation was no longer profitable, and most colonies were left alone or actively protected. Some species are now increasing in numbers, apparently as a result of the mid-20th century’s decimation of Antarctic whales, which compete with penguins for the krill (minute crustaceans) on which both feed. Penguin populations, however, are highly vulnerable to changes in climate and ocean temperature, including recent global warming. Penguins also are very sensitive to depletion of local fish populations by humans.

Natural history:

Reproduction

Many features of the penguin life cycle vary with body size and geographic distribution; the chronology of breeding may also vary within a species in relation to latitude. The majority of species breed only once each year. Certain species, such as the African penguin (Spheniscus demersus), probably other members of this genus, and the blue penguin, breed twice a year. The king penguin breeds twice in three years. One egg is laid by the emperor and king penguins; all others lay two or occasionally three. Most penguins begin breeding in the austral (southern) spring or summer. King penguins are on a 14- to 18-month cycle, and the timing of an individual pair depends on the success or failure of the previous breeding attempt. Some populations of the gentoo penguin (Pygoscelis papua) also breed in winter. The breeding of the emperor penguin begins in autumn, apparently timed so that the long developmental period will produce the young in midsummer, when their chances of survival are greatest.

The gentoo, which has a circumpolar distribution, is notable for its lack of synchrony among populations, but otherwise its breeding schedule is essentially comparable to that of most other species. In the Crozet Islands off southern Africa, for example, egg laying takes place in July. The two eggs are incubated for 35 or 36 days, and the rearing of the chick takes two months. The last immature birds go to sea in January.

Many types of visual and vocal displays are employed between the arrival of the birds at the colony and their departure. Courtship calls are used during pairing and to a lesser degree during the succeeding phases of breeding. There are marked vocal differences between sexes in the emperor penguin and the king penguin and less-marked dimorphisms in some other species. Upon arrival at the colony each bird returns to the nest that it left the previous year and generally rejoins its mate of the previous year, unless the death of the latter forces it to choose another partner. This applies even to the emperor penguin, which is capable of finding its mate despite the absence of a nest and the large size of the colony.

The displays that occur with the reassembly of the colony and the finding of mates, as well as those preceding copulation, are quite similar among the majority of species, but the accompanying vocalizations are more diverse. Various species have been described as trumpeting, croaking, cackling, and cooing; members of the genus Spheniscus are called jackass penguins for the braying sounds they make. The behaviour of experienced older birds is more elaborate and more effective than that of younger individuals. For example, Adélie penguins (Pygoscelis adeliae) may return to the reproductive colony from their third year onward but do not breed successfully until their fifth or sixth year.

Incubation of eggs is performed by both sexes in all species except the emperor penguin, in which it is done exclusively by the male, and it is begun immediately after egg laying. With the advent of incubation, the bustle and myriad cries that characterized mating give way to quiet and inactivity. Faulty incubation behaviour by inexperienced birds frequently results in the abandonment or breakage of eggs. The mortality rate (eggs and chicks) is very important at the egg stage, varying from year to year depending on climatic conditions, the percentage of young birds in the reproductive population, and the pressure of predation. In general, mortality (eggs and chicks) is from 40 to 80 percent of the eggs laid. In coastal colonies predators include, in order of importance: skuas, sheathbills, and the giant petrel. On the Australian, African, and South American continents, the nocturnal habits of certain penguins and the fact that they nest in burrows substantially limit predation, which is mostly by gulls and man.

Following egg laying, the female usually departs for the sea to feed, returning to relieve her mate after about 10 to 20 days. Thereafter, father and mother alternate in periods of a week or two. The female emperor penguin, however, must often walk 80 to 160 km (50 to 100 miles) from the colony to the sea and does not return until the end of the incubation period. During the 64-day incubation period, which extends through the height of the Antarctic winter, the male emperor penguin incubates the egg, holding it on his feet and living on stored fat reserves. During violent winter storms, members of the colony gather for mutual protection from wind and cold in tightly packed crowds called huddles.

Emergence from the shell takes 24 to 48 hours, during which the brooding parent is particularly irritable. The chick shows feeding behaviour immediately on hatching, receiving a regurgitated “soup” of crustaceans or fish by inserting its bill into the open mouth of the parent. During its early days the young bird is sheltered under the body of one of its parents, who take turns foraging and brooding. Growing larger, the young bird remains at a parent’s side, although the fledgling is able to maintain its body heat and move about alone. The chick then joins 100 or more of its contemporaries in a nursery group, or crèche, sometimes guarded by a few adults, while both its parents forage at sea. Upon returning with food, the parent calls its chick from the crèche and is able to distinguish it from other chicks (which frequently respond) by voice and appearance.

During the breeding season the number of “unemployed” adults in the colony increases with the addition of those who have lost eggs or chicks. In emperor penguin colonies, these unemployed birds often interfere with parents that have young and cause increased mortality. During the crèche stage the fuzzy down that has covered the chick since hatching is replaced by a coat of short stiff feathers, which are similar to those of the adult but usually somewhat different in colour. Once this molt is complete, the juvenile leaves the colony to seek its own food at sea.

The period of growth of the young bird from hatching to complete independence varies from two months, in the smallest species of the genus Eudyptula, to 51/2 months in the emperor and 12 to 14 months in the king penguin.

Adult penguins molt all of their feathers once a year following the breeding period. While in molt the bird is unable to enter the water and instead withdraws to a communal molting site usually situated in a sheltered area away from the colony. The duration of the molt varies from about two weeks in small species to more than a month in the larger ones.

The principal enemies of penguins at sea are the leopard seal and the killer whale (orca). Seals also take penguins near Australia, New Zealand, and other subantarctic regions.

Locomotion and orientation

Penguins are adapted for rapid locomotion in water, in which the wings, or flippers, are used for propulsion; the birds “fly” underwater. When moving at high speed, they frequently leave the water in leaps that may carry them a metre or more through the air; it is during this time that they breathe.

On land, penguins are much more awkward, even amusing, as they rock from side to side as they walk. Despite their short legs, however, penguins can run with surprising speed. Some, such as the northern rockhopper (Eudyptes moseleyi), the southern rockhopper (E. chrysocome), and Adélie penguins, move among rocks with agility, using the flippers for balance. On snow or ice, many penguins “toboggan,” sliding on the belly as they propel themselves with the feet and flippers. The flippers, along with the beak, are the prime weapons in defense and attack.

Scientists have long wondered how penguins are able to find their way back to their colonies from far out at sea, where currents may have carried them great distances. Also perplexing is how they are able to direct themselves correctly on land in the absence of clear-cut landmarks. Studies of penguins transported to the interior of Antarctica have found that they are able to find their way back to the ocean by using the sun as a directional aid. It is probable that the same means of orientation is used at sea. Upon approaching the coast they are able to recognize features of the shoreline and ocean bottom.

Food habits

The type of food utilized varies with the species, the geographic region, and the time of year. Most of the smaller southern penguins feed primarily upon krill, which attain high densities in the rich, well-oxygenated Antarctic waters. Cephalopods (squid and cuttlefish) and small fishes may form substantial fractions of the food, and in a few, such as the African penguin, fish is the basic element of the diet. The total weight of food consumed by a large penguin colony is prodigious, often exceeding several tons per day.

Form and function

The penguins are highly specialized for their flightless aquatic existence. The feet are located much farther back than those of other birds, with the result that the bird carries itself mostly upright; its walk can thus be described as plantigrade (i.e., on the soles). The sole comprises the whole foot instead of just the toes, as in other birds. The most notable characteristic of the group is the transformation of the forelimb into a paddle. This is accompanied by a body morphology particularly adapted to movement in a liquid medium. The thoracic (rib) cage is well developed, and the sternum bears a pronounced keel for the attachment of the pectoral muscles, which move the flippers. The flipper has the same skeletal base as the wing of flying birds but with its elements shortened and flattened, producing a relatively rigid limb covered with very short feathers—an ideal organ for rapid propulsion. The body plumage likewise consists of very short feathers, which minimize friction and turbulence. The density of the plumage and the layer of air that it retains provide almost complete insulation of the body.

Insulation of the bird’s body is particularly important for Antarctic species that live in water that is always below 0 °C (32 °F). The cooling power of seawater at −1.9 °C (28.6 °F) is equal to that of a temperature of −20 °C (−4 °F) with a wind of 110 km (70 miles) per hour. The skin is insulated by a layer of air trapped under the plumage, and the only bare skin in direct contact with the water is that of the feet. In the case of the emperor penguin on land, the feet are in almost constant contact with ice. The skin temperature is in the neighbourhood of 0 °C, and snow does not melt upon contact. This is possible because of remarkable anatomical arrangements in the lower limb, whereby closely adjacent arteries and veins form a system of heat exchange between opposing flows of blood. This arrangement permits cooled blood from the feet to absorb heat from outflowing blood, providing maximum economy of heat consistent with the functioning of the foot.

Like other seabirds, penguins have salt glands that enable them to ingest salt from seawater. Excess chloride is excreted in the form of a solution the concentration of which is greater than that of seawater. These glands are located above the eyes and are already functional in the young chick, which begins to consume food of marine origin from its first day of life.

Recent research has shown that the species most isolated geographically, such as the emperor penguin, can be subject to diseases. Some, such as the Adélie penguin, carry in their bodies trace amounts of pollutants, albeit in lower quantities than are found in many birds that live closer to humans.

Evidence from paleontology indicates that the penguins and the order Procellariiformes (albatrosses, shearwaters, and petrels) had a common origin. Both groups are represented by well-defined fossils dating to about 50 million years ago. The flightless sphenisciform line produced a number of distinctive side branches, all recognizably penguins, some giant in size. All of the fossil remains of penguins have been collected within the zone of the present-day distribution of the Sphenisciformes. Some apparently lived in warmer regions than do most of today’s penguins.

Phylogenetic analysis of living and fossil penguins shows that the group evolved a large body size early in its history. For example, two of the largest fossil penguins known—Icadyptes, which stood some 1.5 metres (about 5 feet) tall, and math, which stood about 1.8 metres (6 feet) tall—date to the Eocene Epoch (56 million to 33.9 million years ago). Living penguins make up a separate lineage characterized by smaller, highly aquatic species that began about 8 million years ago. The comparatively small size of living penguins is thus a geologically recent phenomenon that postdates the original radiation of giant penguins.

Additional Information

Penguins are a family of 17 to 19 species of birds that live primarily in the Southern Hemisphere. They include the tiny blue penguins of Australia and New Zealand, the majestic emperor penguins of Antarctica and king penguins found on many sub- Antarctic islands, the endangered African penguin and the Galápagos penguin—the only penguin to be found north of the equator.

Though they are birds, penguins have flippers instead of wings. They cannot fly and on land they waddle walking upright—though when snow conditions are right they will slide on their bellies. In the water they are expert swimmers and divers, and some species can reach speeds of up to 15 miles per hour. The penguin’s distinctive coloring—black body with white belly—helps camouflage the bird in the water as it searches for meals of small shrimp, fish, crabs and squid.

Jai Ganesh · 2025-09-05 18:12:25

2381) Niagra Falls

Gist

What makes Niagara Falls a natural wonder? Statistically speaking, Niagara Falls is recognized as having the greatest flow rate of any waterfall throughout the globe. The falls have more than six million cubic feet (168,000 cubic meters) flow over the top of the falls every minute during the peak season.

Niagara Falls is a group of three waterfalls—American, Bridal Veil, and Horseshoe Falls—located on the Niagara River at the border between Ontario, Canada, and New York, USA. Known for the immense flow of water and spectacular views, the falls have the highest flow rate of any waterfall globally. The site is a popular tourist attraction, a source of hydroelectric power, and home to Niagara Falls State Park, the oldest state park in the United States.

The falls consist of the American Falls, the Bridal Veil Falls, and the much larger Horseshoe Falls.

Summary

Niagara Falls[a] is a group of three waterfalls at the southern end of Niagara Gorge, spanning the border between the province of Ontario in Canada and the state of New York in the United States. The largest of the three is Horseshoe Falls, which straddles the international border of the two countries. It is also known as the Canadian Falls. The smaller American Falls and Bridal Veil Falls lie within the United States. Bridal Veil Falls is separated from Horseshoe Falls by Goat Island and from American Falls by Luna Island, with both islands situated in New York.

Formed by the Niagara River, which drains Lake Erie into Lake Ontario, the combined falls have the highest flow rate of any waterfall in North America that has a vertical drop of more than 50 m (164 ft). During peak daytime tourist hours, more than 168,000 {m}^{3} (5.9 million cu ft) of water goes over the crest of the falls every minute. Horseshoe Falls is the most powerful waterfall in North America, as measured by flow rate. Niagara Falls is famed for its beauty and is a valuable source of hydroelectric power. Balancing recreational, commercial, and industrial uses has been a challenge for the stewards of the falls since the 19th century.

Niagara Falls is 27 km (17 mi) northwest of Buffalo, New York, and 69 km (43 mi) southeast of Toronto, between the twin cities of Niagara Falls, Ontario, and Niagara Falls, New York. Niagara Falls was formed when glaciers receded at the end of the Wisconsin glaciation (the last ice age), and water from the newly formed Great Lakes carved a path over and through the Niagara Escarpment en route to the Atlantic Ocean.

Details

Niagara Falls, waterfall on the Niagara River in northeastern North America, one of the continent’s most famous spectacles. The falls lie on the border between Ontario, Canada, and New York state, U.S. For many decades the falls were an attraction for honeymooners and for such stunts as walking over the falls on a tightrope or going over them in a barrel. Increasingly, however, the appeal of the site has become its beauty and uniqueness as a physical phenomenon.

The falls are in two principal parts, separated by Goat Island. The larger division, adjoining the left, or Canadian, bank, is Horseshoe Falls; its height is 188 feet (57 metres), and the length of its curving crest line is about 2,200 feet (670 metres). The American Falls, adjoining the right bank, are 190 feet (58 metres) high and 1,060 feet (320 metres) across.

The formation of the Niagara gorge (downriver) and the maintenance of the falls as a cataract depend upon peculiar geologic conditions. The rock strata from the Silurian Period (about 444 to 419 million years ago) in the Niagara gorge are nearly horizontal, dipping southward only about 20 feet per mile (almost 4 metres per km). An upper layer of hard dolomite is underlain by softer layers of shale. Water exerts hydrostatic pressure and only slowly dissolves the dolomite after infiltrating its joints. Dolomite blocks fall away as water from above infiltrates and rapidly erodes the shale at the falls itself. The disposition of the rock strata provides the conditions for keeping the water constantly falling vertically from an overhanging ledge during a long period of recession (movement upstream) of the cataract. As blocks of dolomite are undercut, they fall off and are rapidly destroyed by the falling water, further facilitating the retreat of the falls and the maintenance of a vertical cataract.

The water flowing over the falls is free of sediment, and its clearness contributes to the beauty of the cataract. In recognition of the importance of the waterfall as a great natural spectacle, the province of Ontario and the state of New York retained or acquired title to the adjacent lands and converted them into public parks.

The very large diversion of water above the falls for hydroelectric power purposes has lessened the rate of erosion. Elaborate control works upstream from the falls have maintained an even distribution of flow across both the U.S. and Canadian cataracts, thereby preserving the curtains of the waterfalls. A large part of the great river above the falls is diverted and disappears into four great tunnels for use in the power plants downstream. Because of concern over the possibility of major rockfalls, water was diverted from the American Falls in 1969, and some cementing of the bedrock was done; an extensive boring and sampling program was also carried out. River flow was returned to the American Falls in November of that year, and it was decided that safety measures for the viewing public should be implemented and that measures to stem natural processes were both too expensive and undesirable.

Excellent views of the falls are obtained from Queen Victoria Park on the Canadian side; from Prospect Point on the U.S. side at the edge of the American Falls; and from Rainbow Bridge, which spans the Niagara gorge about 1,000 feet (300 metres) downstream from Prospect Point. Visitors may cross from the U.S. shore to Goat Island by footbridge and may take an elevator to the foot of the falls and visit the Cave of the Winds behind the curtain of falling water. The Horseshoe Falls, which carry about 90 percent of the river’s discharge, receded upstream at an average rate of about 5.5 feet (1.7 metres) per year in 1842–1905. Thereafter, control works and the diversion of water decreased the erosion rate, which is presently so slow at the American Falls that large blocks of dolomite accumulate at the base of the falls, threatening to turn it into rapids.

Additional Information

Situated between the state of New York and the province of Ontario, Niagara Falls is one of the most spectacular natural wonders in North America. This series of waterfallsis on the Niagara River, which flows between the United States and Canada from Lake Erie to Lake Ontario. The falls are about 17 miles (27 kilometers) northwest of Buffalo, New York. The industrial city and tourist center of Niagara Falls, New York, is adjacent to the American side of the falls. Niagara Falls, Ontario, Canada, is across the river.

The falls are divided into two parts by Goat Island. The larger portion, on the southwest side, is the Canadian falls, known as the Horseshoe Falls. It measures 2,600 feet (790 meters) along its curve and drops 162 feet (49 meters). The smaller American Falls is northeast of Goat Island. It is 1,000 feet (305 meters) across and drops about 167 feet (51 meters). Between the American Falls and Goat Island are the small Luna Island and the small Luna, or Bridal Veil, Falls.

Just before flowing over the ledge, the American stream is only about 3 1/2 feet (1 meter) deep. The Canadian stream is about 20 feet (6 meters) deep and carries some 95 percent of the Niagara River’s water.

Every minute about 12,000,000 cubic feet (340,000 cubic meters), or 379,000 tons, of water pours in torrents over the cliffs of the falls of Niagara. As the water plunges from the brink of the falls, it fills the air with a silvery mist, which under the sunlight displays many rainbows. The plunging water also sends out a never-ending roar as it strikes the bottom. For this reason the Haudenosaunee (Iroquois) people called the falls Niagara, meaning “thunder of waters.”

The plunging water has worn the lower rocks away so that there are caves behind the sheets of water of both falls. Sightseers may enter the Cave of the Winds at the foot of the American Falls and get an unusual view. The Horseshoe Falls have carved a plunge basin 192 feet (59 meters) deep.

Both the United States and Canadian governments have built parks, viewing platforms, paths, and highways. The Niagara Reservation State Park was established in 1885 and is New York’s oldest state park. It includes an observation tower, elevators that descend into the gorge at the base of the American Falls, and boat trips into the waters at the base of the Horseshoe Falls.

The park area has long been a tourist site and a favorite spot for couples to spend their honeymoons. At night colored lights illuminate the falls.

Almost all the drainage from four of the Great Lakes pours over the crest of Niagara Falls. This tremendous volume of water is used to generate power in six hydroelectric plants. They develop a maximum of about 5 3/4 million horsepower, some 55 percent on the American side and about 45 percent on the Canadian. The plants draw water from the river above the falls through canals. Near each plant the water drops through penstocks to powerhouses on the Niagara River below the falls. There it turns turbine generators.

The control of Niagara Falls between the United States and Canada has long offered the world an example of international cooperation. A treaty in 1910 and later agreements fixed the amounts of water that could be diverted. An international Niagara Control Board was established in 1923.

In 1950 the two countries signed a new treaty that specified the minimum flow to be maintained over the falls. This treaty made possible greater hydroelectric development. It provides that 100,000 cubic feet (2,830 cubic meters) per second of water must flow over the falls during the tourist season in the daytime and 50,000 (1,415) at night and during the off-tourist season in the daytime. The remainder is equally divided between Canada and the United States. An average of 202,300 cubic feet (5,729 cubic meters) per second flows over the falls.

Between 1954 and 1958 the United States and Canada completed the Niagara Remedial Works Project. This enormous operation checked erosion with a gated control structure, excavations, and fills.

The Hydro-Electric Power Commission of Ontario completed the Sir Adam Beck-Niagara Generating Station No. 1 in 1925 and No. 2 in 1958. The combined capacity of the plants is 1,443,000 kilowatts.

In 1957 the United States Congress approved the construction of the Niagara Power Project by the Power Authority of the State of New York. It has a capacity of 2,190,000 kilowatts. The first electric current from the project was delivered in 1961.

The falls of Niagara are about 25,000 years old. The hard rock (Lockport dolomite) at the brink of the falls is much older. It was made on the bed of an inland sea in the Silurian period (about 443 million to 419 million years ago). Gradually the limy sediment hardened to stone—either limestone or dolomite, a limestone with magnesium.

Later the Niagara region was raised in a widespread uplift centered in Michigan. Streams wore down the land. The layer of tough rock, however, resisted erosion. The edge of the deposit formed a great cliff—the Niagara escarpment. It runs west from Rochester, New York, between Lakes Erie and Ontario, then swings northward through the province of Ontario. It is capped by hard Niagara limestone or Lockport dolomite.

Glaciers covered the Niagara region during the Ice Age that took place during the Pleistocene Epoch (about 2.6 million to 11,700 years ago). As the last glacier retreated, it left Lake Erie at its southern edge. Water from the lake began to spill over the Niagara escarpment into the Ontario basin below, just south of where Queenston and Lewiston now stand.

The new falls did not wear away the dolomite caprock as fast as it churned away the softer rock below. From time to time blocks of the undermined caprock broke off. The falls worked back toward Lake Erie, forming a steep-walled gorge.

Niagara’s rate of cutting has changed many times. It started slowly, for at first the river drained Lake Erie only. Lakes Superior, Michigan, and Huron had a northerly outlet. The drainage changed as glaciers retreated. Water from all four lakes then poured over the falls. When the river spread to the point where the famous whirlpool now is, it reached an ancient valley that had cut into the dolomite from the west. Later the valley filled with glacial debris. The river wore away the soft material, forming the 60-acre (24- hectare) basin.

Louis Hennepin, a priest who accompanied the French explorer René-Robert Cavelier, sieur de La Salle, was the first European to view Niagara Falls, in 1678. The site was of strategic use to the British and French in the struggle to control the Great Lakes. The British built Fort Schlosser there in 1761.

w=1500,h=1000

Jai Ganesh · 2025-09-06 22:44:37

2382) Congo River

Gist

The deepest river in the world is the Congo River in Africa, with recorded depths reaching at least 220 meters (720 feet). Recognized by Guinness World Records, its maximum depth surpasses that of any other river and was confirmed by scientists in 2008.

Summary

The basin of the deepest river in the world provides food, water, medicines and transportation to about 75 million people, according to Yale University’s Global Forest Atlas.

1 . Where does the Congo river flow through?
The Congo is the deepest river in the world. Its headwaters are in the north-east of Zambia, between Lake Tanganyika and Lake Nyasa (Malawi), 1760 metres above sea level; it flows into the Atlantic Ocean.

The Congo river flows through the Republic of the Congo, the Democratic Republic of the Congo, the Central African Republic, western Zambia, northern Angola, Cameroon and Tanzania. The lower course of the Congo river has large gorges and falls, which makes it one of the most dangerous rivers.

2 . How deep and how long is the Congo river?
The Congo river, formerly known as the Zaire, is the deepest river in the world: at some points the water can be up to 220 metres deep; the basin has a surface area of 3,457,000 square kilometres.

The Congo river is 4,700 kilometres long, which makes it the second longest river in Africa, the tenth longest river in the world and the second largest river by discharge volume in the world, only after the Amazon.

3 . What are the environmental threats in the Congo river basin?
One of the main threats in the Congo river basin is deforestation to accommodate modern agricultural practices; moreover, industrial logging accelerates the rate of deforestation.

The other major threat is food demand due to rapid population growth in the region, which leads to excessive hunting of wild animals such as bats, monkeys, rats and snakes.

Summary

he Congo River, formerly also known as the Zaire River, is the second-longest river in Africa, shorter only than the Nile, as well as the third-largest river in the world by discharge volume, following the Amazon and Ganges–Brahmaputra rivers. It is the world's deepest recorded river, with measured depths of around 220 m (720 ft). The Congo–Lualaba–Luvua–Luapula–Chambeshi River system has an overall length of 4,700 km (2,900 mi), which makes it the world's ninth-longest river. The Chambeshi is a tributary of the Lualaba River, and Lualaba is the name of the Congo River upstream of Boyoma Falls, extending for 1,800 km (1,100 mi).

Measured along with the Lualaba, the main tributary, the Congo River has a total length of 4,370 km (2,720 mi). It is the only major river to cross the equator twice. The Congo Basin has a total area of about 4,000,000 sq km (1,500,000 sq mi), or 13% of the entire African landmass.

Name

The name Congo/Kongo originates from the Kingdom of Kongo once located on the southern bank of the river. The kingdom in turn was named after the indigenous Bantu Kongo people, known in the 17th century as "Esikongo". South of the Kingdom of Kongo proper lay the similarly named Kakongo kingdom, mentioned in 1535. Abraham Ortelius labelled "Manicongo" as the city at the mouth of the river in his world map of 1564. The tribal names in Kongo possibly derive from a word for a public gathering or tribal assembly. The modern name of the Kongo people or Bakongo was introduced in the early 20th century.

The name Zaire is from a Portuguese adaptation of a Kikongo word, nzere ("river"), a truncation of nzadi o nzere ("river swallowing rivers"). The river was known as Zaire during the 16th and 17th centuries; Congo seems to have replaced Zaire gradually in English usage during the 18th century, and Congo is the preferred English name in 19th-century literature, although references to Zahir or Zaire as the name used by the inhabitants remained common. The Democratic Republic of the Congo and the Republic of the Congo are named after it, as was the previous Republic of the Congo which had gained independence in 1960 from the Belgian Congo. The Republic of Zaire during 1971–1997 was also named after the river's name in French and Portuguese.

Details

Congo River, river in west-central Africa. With a length of 2,900 miles (4,700 km), it is the continent’s second longest river, after the Nile. It rises in the highlands of northeastern Zambia between Lakes Tanganyika and Nyasa (Malawi) as the Chambeshi River at an elevation of 5,760 feet (1,760 metres) above sea level and at a distance of about 430 miles (700 km) from the Indian Ocean. Its course then takes the form of a giant counterclockwise arc, flowing to the northwest, west, and southwest before draining into the Atlantic Ocean at Banana (Banane) in the Democratic Republic of the Congo. Its drainage basin, covering an area of 1,335,000 square miles (3,457,000 square km), takes in almost the entire territory of that country, as well as most of the Republic of the Congo, the Central African Republic, eastern Zambia, and northern Angola and parts of Cameroon and Tanzania.

With its many tributaries, the Congo forms the continent’s largest network of navigable waterways. Navigability, however, is limited by an insurmountable obstacle: a series of 32 cataracts over the river’s lower course, including the famous Inga Falls. These cataracts render the Congo unnavigable between the seaport of Matadi, at the head of the Congo estuary, and Malebo Pool, a lakelike expansion of the river. It was on opposite banks of Malebo Pool—which represents the point of departure of inland navigation—that the capitals of the former states of the French Congo and the Belgian Congo were founded: on the left bank Kinshasa (formerly Léopoldville), now the capital of the Democratic Republic of the Congo, and on the right bank Brazzaville, now the capital of the Republic of the Congo.

The Amazon and the Congo are the two great rivers of the world that flow out of equatorial zones where heavy rainfall occurs throughout all or almost all of the year. Upstream from Malebo Pool, the Congo basin receives an average of about 60 inches (1,500 mm) of rain a year, of which more than one-fourth is discharged into the Atlantic. The drainage basin of the Congo is, however, only about half the size of that of the Amazon, and the Congo’s rate of flow—1,450,000 cubic feet (41,000 cubic metres) per second at its mouth—is considerably less than the Amazon’s flow of more than 6,180,000 cubic feet (175,000 cubic metres) per second.

While the Chambeshi River, as the remotest source, may form the Congo’s original main stream in terms of the river’s length, it is another tributary—the Lualaba, which rises near Musofi in southeastern Democratic Republic of the Congo—that carries the greatest quantity of water and thus may be considered as forming the Congo’s original main stream in terms of water volume.

When the river first became known to Europeans at the end of the 15th century, they called it the Zaire, a corruption of a word that is variously given as nzari, nzali, njali, nzaddi, and niadi and that simply means “river” in local African languages. It was only in the early years of the 18th century that the river was first called the “Rio Congo,” a name taken from the kingdom of Kongo that had been situated along the lower course of the river. During the period (1971–97) when the Democratic Republic of the Congo was called Zaire, the government also renamed the river the Zaire. Even during that time, however, the river continued to be known throughout the world as the Congo. To the literary-minded the river is evocative of the famous 1902 short story “Heart of Darkness” by Joseph Conrad. His book conjured up an atmosphere of foreboding, treachery, greed, and exploitation. Today, however, the Congo appears as the key to the economic development of the central African interior.

Physical features:

Physiography

The expression “Congo basin,” strictly speaking, refers to the hydrographic basin. This is not only vast but is also covered with a dense and ramified network of tributaries, subtributaries, and small rivers—with the exception of the sandy plateaus in the southwest.

The Congo basin is the most clearly distinguished of the various geographic depressions situated between the Sahara to the north, the Atlantic Ocean to the south and west, and the region of the East African lakes to the east. In this basin, a fan-shaped web of tributaries flows downward along concentric slopes that range from 900 to 1,500 feet (275 to 460 metres) in elevation and that enclose a central depression. The basin itself stretches for more than 1,200 miles (1,900 km) from north to south (from the Congo–Lake Chad watershed to the interior plateaus of Angola) and also measures about 1,200 miles from the Atlantic in the west to the Nile-Congo watershed in the east.

The central part of the Congo basin—often called the cuvette (literally “saucer” or “shallow bowl”)—is an immense depression containing Quaternary alluvial deposits that rest on thick sediments of continental origin, consisting principally of sands and sandstones. These underlying sediments form outcrops in valley floors at the eastern edge of the cuvette. The filling of the cuvette, however, began much earlier. Boreholes have revealed that since late Precambrian times (i.e., since at least 570 million years ago) considerable sediment has accumulated, derived from the erosion of formations situated around the periphery of the cuvette. The arrangement of surface relief, thick depositional strata, and substratum in amphitheatre-like fashion around the main Congo channel, which has been uniform across time, is evidence of a persistent tendency to subsidence in this part of the continent. This subsidence is accompanied by uplifting on the edges of the cuvette, principally on its eastern side—which has also been influenced by the formation of the Western Rift Valley.

From its sources to its mouth, the Congo River system has three contrasting sections—the upper Congo, middle Congo, and lower Congo. The upper reaches are characterized by three features—confluences, lakes, and waterfalls or rapids. To begin with, several streams of approximately equal size unite to form the river. In a little more than 60 miles (100 km), the upper Lualaba joins the Luvua and then the Lukuga. Each stream for part of its course undergoes at least a lacustrine type of expansion, even when it does not form a lake. Thus, Lake Upemba occurs on the upper Lualaba; Lakes Bangweulu and Mweru occur on the Chambeshi–Luapula–Luvua system; and Lake Tanganyika, which is fed by the Ruzizi (flowing from Lake Kivu) and by the Malagarasi, itself flows into the Lukuga. Rapids occur not only along the headstreams but also in several places along the course of the main stream. Navigation thus is possible only along sections of the upper Congo by vessels of low tonnage. Even so, these stretches are in danger of being overgrown by aquatic vegetation, particularly water hyacinths.

Kisangani (formerly Stanleyville)—located just downstream of the Boyoma Falls, a series of seven cataracts—marks the real beginning, upriver, of the navigable Congo. This central part of the river flows steadily for more than 1,000 miles (1,600 km) to within 22 miles (35 km) of Kinshasa. Its course at first is narrow but soon grows wider, after which many islands occur in midstream. This change in the character of the river corresponds to its entry into its alluvial plain. From that point onward, with the exception of a few rare narrow sections, the Congo divides into several arms, separated by strings of islands. It increases from a width of more than 3.5 miles (5.5 km) downstream from Isangi (where the Lomami enters the Congo) to a width of 5 to 7 miles (8 to 11 km) and on occasion—for example, at the mouth of the Mongala—to 8 miles (13 km). Beyond the natural levees (formed by silt deposits) occurring on either bank, some areas are subjected to extensive flooding that increases the river’s bounds still further. It is not always easy to distinguish such areas from the “rain swamps” in regions lying between rivers. The middle course of the Congo ends in a narrow section called the Chenal (“Channel”), or Couloir (“Corridor”). Between banks no more than half a mile to a mile wide, the riverbed deepens and the current becomes rapid, flowing through a valley that cuts down several hundreds of yards deep into the soft sandstone bedrock of the Batéké Plateau. Along this central reach the Congo receives its principal tributaries, primarily the Ubangi and the Sangha on the right bank and the Kwa on the left bank. An enormous increase in the average rate of flow results, rising from less than 250,000 cubic feet (7,000 cubic metres) a second at Kisangani to nearly its maximum flow at Kinshasa.

Upon leaving the Chenal, the Congo divides into two branches, forming Malebo Pool, a vast lacustrine area about 15 by 17 miles (24 by 27 km), which marks the end of the middle Congo. Immediately downstream occur the first waterfalls of the final section of the river’s course. Cataracts and rapids are grouped into two series, separated by a fairly calm central reach, in which the elevation drops from a little less than 900 feet (275 metres) to a few yards above sea level. The Congo’s estuary begins at Matadi, downstream from the rapids that close off the interior Congo; 83 miles (134 km) in length, it forms the border between Angola and the Democratic Republic of the Congo. At first the estuary is narrow—less than half a mile to about a mile and a half in width—with a central channel 65 to 80 feet (20 to 24 metres) deep, but it widens downstream of Boma. There the river, obstructed by islands, divides into several arms, and in some places the depth does not exceed 20 to 25 feet (6 to 7.5 metres), which makes dredging necessary to allow oceangoing vessels to reach Matadi. Beyond the estuary’s mouth, the course of the Congo continues offshore as a deep underwater canyon that extends for a distance of about 125 miles (200 km).

Hydrology of the Congo River

The Congo has a regular flow, which is fed by rains throughout the year. At Kinshasa the flow has for many years remained between the high level of 2,310,000 cubic feet (65,000 cubic metres) per second, recorded during the flood of 1908, and the low level of 756,000 cubic feet (21,000 cubic metres) per second, recorded in 1905. During the unusual flood of 1962, however, by far the highest for a century, the flow probably exceeded 2,600,000 cubic feet (73,000 cubic metres) per second.

At Brazzaville and Kinshasa, the river’s regime is characterized by a main maximum at the end of the year and a secondary maximum in May, as well as by a major low level during July and a secondary low level during March and April. In reality, the downstream regime of the Congo represents climatic influence extending over 20° of latitude on both sides of the Equator a distance of some 1,400 miles (2,250 km). Each tributary in its course modifies the level of the main stream. Thus, for example, the low level in July at Malebo Pool results from two factors: a drought that occurs for several months in the southern part of the basin at that time, as well as a delay before the floods of the Ubangi tributary flowing down from the north arrive, which does not happen before August. The Congo basin is so vast that no single meteorologic circumstance is capable of disturbing the slow movement of the waters’ rise and fall. The annual fluctuations may alter drastically, however, when floodwaters from different tributaries that normally coincide with each other arrive at different times.

Lake Tanganyika, apart from brief seiches caused by wind drift and sudden changes in atmospheric pressure, may experience considerable variations in its water level from year to year. In 1960, for example, its waters flooded parts of Kalemi, Democratic Republic of the Congo, and Bujumbura, Burundi. A series of particularly rainy years followed by a blocking of the outlet by floating vegetation may explain this phenomenon.

Climate

Typical climate in regions through which the Congo flows is that of Yangambi, a town situated on the river’s right bank slightly north of the Equator and a little downstream of Kisangani. Humidity is high throughout the year, and annual rainfall amounts to 67 inches (1,700 mm) and occurs fairly regularly; even in the driest month the rainfall totals more than 3 inches (76 mm). Temperatures are also uniformly high throughout the year, and there is little diurnal variability. The average temperature at Yangambi is in the mid-70s F (mid-20s C).

From the pluviometric equator (an imaginary east-west line indicating the region of heaviest rainfall), which is situated slightly to the north of the geographic equator, the amount of rainfall decreases regularly in proportion to latitude. The northernmost points of the basin, situated in the Central African Republic, receive only from 8 to 16 inches (200 to 400 mm) less during the course of a year than points near the Equator. The dry season, however, lasts for four or five months, and there is only one annual rainfall maximum, which occurs in summer. In the far southern part of the basin, at a latitude of 12° S, the climate becomes definitely Sudanic in character, with marked dry and wet seasons of approximately equal length and with rainfall of about 49 inches (1,250 mm) a year.

Plant life

The Congo basin is home to the second largest rainforest in the world. The equatorial climate that prevails over a significant part of the Congo basin is coextensive with a dense evergreen forest. The Congolese forest spreads out over the central depression, extending continuously from about 4° N to about 5° S; it is interrupted only by clearings, many of which have a natural origin. The forest region is bordered on either side by belts of savanna (grassy parkland). The forest and savanna often meet imperceptibly, blending together in a mosaic pattern; more rarely, strips of forest invade the grassland. Farther away from the Equator, and to the extent that the Sudanic features of the climate become evident, the wooded savanna region, with its thin deciduous forest, is progressively reached.

As it courses through the solid mass of the Congolese forest, the Congo and its tributaries are bordered by discontinuous grassy strips. Meadows of Echinochloa (a type of grass), papyrus, and Cyperaceae (sedge) occupy abandoned river channels, fringe the banks, or, behind a curtain of forest, blanket the depressions in the centre of the islands, They also spring up on sandbanks, as well as on the downstream ends of islands that are fertilized by the floods. A shrub, Alchornea, frequently marks the transition to the high forest that grows on the levees behind the banks.

Animal life

The animal life of the Congo basin is identified to a certain extent with that of the equatorial forest, which is sharply distinct from the wildlife of the savannas. Within this equatorial domain, the Congo and its principal tributaries form a separate ecological milieu. The animal population of the great waterways often has fewer affinities with the neighbouring marshes or the forests on dry land than it has with other river systems, whether of the coastal region or the savannas.

Numerous species of fish live in the waters of the Congo; more than 230 have been identified in Malebo Pool and the waters that flow into it alone. The riverine swamps, which often dry up at low water, are inhabited by lungfish, which survive the dry periods buried and encysted in cocoons of mucus. In the wooded marshlands, where the water is the colour of black tea, the black catfish there assume the colour of their environment. The wildlife of the marshes and that of the little parallel streams do not mix with the wildlife of the river itself.

The waters of the Congo contain various kinds of reptiles, of which crocodiles are the most striking species. Semiaquatic tortoises are also found, as are several species of water snakes.

The forest birdlife constitutes, together with the birdlife of the East African mountains, the most specifically indigenous birdlife found on the African continent. In the Congo region more than 265 species typical of the equatorial forest have been recorded. Occasionally or seasonally, however, nontypical birds may be observed. Seabirds, such as the sea swallow, fly upstream from the ocean. Migratory birds from Europe, including the blongios heron and the Ixobrychus minutus (little bittern), pass through the region. Species with a wide distribution within Africa, such as the Egyptian duck, also have been sighted. Ducks, herons, storks, and pelicans are abundantly represented.

Aquatic mammals are rare, consisting of the hippopotamus, two species of otters, and the manatee. The manatee (sea cow), which lives entirely in the water, has been officially identified only on the Sangha tributary but appears to have given rise to some curious legends on the lower Congo, including its association with a creature called Mami Wata (a kind of siren), stories of which were carried by African slaves to the Americas.

The people and the economy:

Life of the river peoples

Three types of environments are found, either juxtaposed or in succession, along the river and its tributaries: the narrower sections, bordered by firm ground; the wider stretches, dotted with islands and accompanied by backwaters; and the zones where flooding occurs or where there are extensive marshes.

Almost all the river peoples engage in fishing. Along the narrow sections, where rapids often occur, fishing is only of interest to a small number of villages. The Enya (Wagenia) of Boyoma Falls and the Manyanga living downstream from Malebo Pool attach fish traps to stakes or to dams built in the rapids themselves. Fishing of a very different nature, notably by poison, is conducted in the marshy areas, where the population is more extensive than might be imagined. Among these peoples are the Ngombe—“water people”—who inhabit the Itimbiri-Ngiri and the triangle formed by the Congo and the Ubangi. Other fisherfolk of the marshes dwell in the lagoons and the flooded forests of the region where the confluence of the Congo and the Alima, Likouala, and Sangha occurs.

Despite unfavourable conditions, all these peoples are also cultivators. They raise dikes, often of monumental size, to plant cassava (manioc) on the land thus sheltered from flooding. Other minor crops, such as sweet potatoes, bananas, and yams, are also found. The Congo basin has the continent’s most important timber resources, but the timber industry is developing slowly, mainly because the interior is so inaccessible and because the cost of transporting timber to the coast is so high.

Few modes of existence have undergone such profound changes as a result of contact with the modern world as has that of the river’s fisherfolk. The growth of the towns on the banks of Malebo Pool as well as the taste of urban dwellers for river fish have served to stimulate fishing by tying it to a cash economy. It is not just a question of villagers smoking fish that they sell to passing traders. Increasingly numerous fishing crews sail up the Congo, the Ubangi, and the Kasai, well above their confluences, to fish in the shallows.

Transportation

The Congo is an important navigational system in Africa. Within the territorial limits of the Democratic Republic of the Congo alone, there are some 8,700 miles (14,000 km) of navigable waterway. Of this total, 650 miles (1,050 km) are accessible at all seasons to barges with capacities between 800 and 1,100 tons, depending upon the height of the water. The amount of goods transported by water—consisting mainly of agricultural produce, wood, minerals, and fuel—is very modest in comparison with the traffic on European rivers (for example, the commercial traffic from the port of Kinshasa does not reach a million tons), but river transport remains essential for communications with regions that are inaccessible by road, especially in the cuvette. The three principal routes, all of which converge on the downstream terminus at Kinshasa on the Malebo Pool, run from Kisangani, from Ilebo (formerly Port-Francqui) on the Kasai, and from Bangui on the Ubangi. River transport, however, falls short of the role it could play in development. It has actually declined since the states of the Congo basin became independent in 1960, because of serious problems with aging equipment, a lack of maintenance of the infrastructure, and the poor functioning of the public waterway agencies. In the Democratic Republic of the Congo only the section from Ilebo to Kinshasa is still important, because it constitutes the river link (the other link being a railway between Kinshasa and Matadi) used to transport the copper production of Katanga to the coast.

This network has fostered economic development in inland areas, far from the coast. Varied activities include the production of palm oil on the banks of the Kwilu, centred on the port of Kikwit, and the establishment of plantations of robusta coffee in the Kisangani area.

Before such developments could be undertaken, however, it was necessary to overcome the barrier to the sea formed by the Congo’s lower course. That feat was accomplished in 1898 with the opening of the railway between Matadi and Léopoldville (now Kinshasa) and in 1934 by the completion of the Congo-Ocean rail line on the right bank between Brazzaville and Pointe-Noire.

While the river system facilitates navigation, it also hinders land transportation. Only a small number of bridges cross the Congo and its tributaries. The Kongolo rail-and-road bridge over the Lualaba was reconstructed in 1968, and a bridge over the Congo at Matadi was opened in 1983. Numerous projects to improve the situation nevertheless exist, notably a link between Kinshasa and Brazzaville. This project has long been under discussion, although to financial obstacles are added difficulties caused by political dissension. Several times since the two countries gained independence in 1960, dissension has interrupted the ferry traffic between the two capitals.

Power

It has been estimated that the hydroelectric potential of the Congo basin amounts to about one-sixth of the known world resources, but only a fraction of this potential has been harnessed. The single site of Inga, just upriver from Matadi, has a power potential estimated at more than 30,000 megawatts. Two hydroelectric projects, called Inga I and Inga II, have been completed there since the independence of the Democratic Republic of the Congo. Further development of the region’s hydropower potential, as outlined in the ambitious “Grand Inga” scheme, would create one of the world’s largest hydroelectric power systems.

Study and exploration

The question of the source of the Congo confronted European explorers from the time that the Portuguese navigator Diogo Cão encountered the river’s mouth in 1482, which he believed to be a strait providing access to the realm of the mythical Prester John, a Christian priest-king. It is virtually certain that, well before the Welsh explorer Henry Morton Stanley arrived in 1877, some 17th-century Capuchin missionaries reached the shores of Malebo Pool. This exploit, however, was not followed up, even by the amply supplied expedition led by James Kingston Tuckey, which was sent out by the British Admiralty in 1816 but was decimated and had to retrace its footsteps even before it had surmounted the cataracts. Preposterous hypotheses about the river continued to be entertained, connecting, for example, the upper Niger to the Congo or maintaining that the Congo and the Nile both flowed from a single great lake in the heart of Africa.

Even after the European discovery of Lake Tanganyika by the British explorers Richard Burton and John Speke (1858), then of the Lualaba (1867) and of Lake Bangweulu (1868) by the Scottish explorer David Livingstone, uncertainty remained—uncertainty that Stanley was to dissipate in the course of his famous expedition in 1876 and 1877 that took him by water from the Lualaba to the Congo’s mouth over a period of nine months. In the interior of the Congo basin and above all on the right bank, the final blank spaces on the map could not be filled in until about 1890, when the exploration of the upper course of the Ubangi was completed.

Additional Information

The Congo River (also known as Zaire River) is the largest river in Africa. Its overall length of 4,700 km (2,922 miles) makes it the second longest in Africa (after the Nile). The river and its tributaries flow through the second largest rain forest area in the world, second only to the Amazon Rainforest in South America.

The river also has the second-largest flow in the world, behind the Amazon, and the second-largest watershed of any river, again trailing the Amazon. Its watershed is a little larger than that of the Mississippi River. Because large parts of the river basin sit north and south of the equator, its flow is steady, as there is always at least one river having a rainy season. The Congo gets its name from the old Kingdom of Kongo which was at the mouth of the river. The Democratic Republic of the Congo and the Republic of the Congo, both countries sitting along the river's banks, are named after it. From 1971 to 1997, the Democratic Republic of the Congo was called Zaire and its government called the river the Zaire River.

The sources of the Congo are in the Highlands and mountains of the East African Rift, as well as Lake Tanganyika and Lake Mweru, which feed the Lualaba River. This then becomes the Congo below Boyoma Falls. The Chambeshi River in Zambia is usually taken as the source of the Congo because of the accepted practice worldwide of using the longest tributary, as with the Nile River.

The Congo flows mostly west from Kisangani just below the falls, then slowly bends southwest, passing by Mbandaka, joining with the Ubangi River, and running into the Pool Malebo (Stanley Pool). Kinshasa (formerly Léopoldville) and Brazzaville are on opposite sides of the river at the Pool, where the river narrows and falls through a few cataracts in deep canyons (collectively known as the Livingstone Falls), running by Matadi and Boma, and into the sea at the small town of Muanda.

History of exploration

The mouth of the Congo was visited by Europeans in 1482, by the Portuguese Diogo Cão, and in 1817, by a British exploration under James Kingston Tuckey that went up the river as far as Isangila. Henry Morton Stanley was the first European to travel along the whole river.

Economic importance

Although the Livingstone Falls stop ships coming in from the sea, almost all of the Congo is navigable in parts, especially between Kinshasa and Kisangani. Railways cross the three major falls that interrupt navigation, and much of the trade of central Africa passes along the river. Goods include copper, palm oil, sugar, coffee, and cotton. The river can also be valuable for hydroelectric power, and Inga Dams below Pool Malebo have been built.

In February of 2005, South Africa's state owned power company, Eskom, said that they had a proposal to increase the amount of electric power that the Inga can make through improvements and the building of a new hydroelectric dam. The project would bring the highest output of the dam to 40 GW, twice that of China's Three Gorges Dam.

Geological history

In the Mesozoic period before the continental drift opened the South Atlantic Ocean, the Congo was the upper part of a river about 12,000 km (7,500 miles) long that flowed west across the parts of Gondwanaland, now called Africa and South America.

rio-congo.jpg.webp

Jai Ganesh · Yesterday 21:28:45

2383) Ostrich

Gist

Ostriches have special features including being the world's largest and fastest flightless bird, with powerful two-toed legs, largest eyes of any land animal, and unique two-toed feet. Their specialized feathers help with temperature regulation, their large wings are used for balance, and their powerful kicks serve as a potent defense mechanism.

Summary

Details

Additional Information

The flightless ostrich is the world's largest bird. They roam African savanna and desert lands and get most of their water from the plants they eat.

Speed and Movement

Though they cannot fly, ostriches are fleet, strong runners. They can sprint up to 43 miles an hour and run over distance at 31 miles an hour. They may use their wings as "rudders" to help them change direction while running. An ostrich's powerful, long legs can cover 10 to 16 feet in a single stride. These legs can also be formidable weapons. Ostrich kicks can kill a human or a potential predator like a lion. Each two-toed foot has a long, sharp claw.

Herds and Reproduction

Ostriches live in small herds that typically contain less than a dozen birds. Alpha males maintain these herds, and mate with the group's dominant hen. The male sometimes mates with others in the group, and wandering males may also mate with lesser hens. All of the group's hens place their eggs in the dominant hen's nest—though her own are given the prominent center place. The dominant hen and male take turns incubating the giant eggs, each one of which weighs as much as two dozen chicken eggs.

Behavior and Diet

Contrary to popular belief, ostriches do not bury their heads in the sand. The old saw probably originates with one of the bird's defensive behaviors. At the approach of trouble, ostriches will lie low and press their long necks to the ground in an attempt to become less visible. Their plumage blends well with sandy soil and, from a distance, gives the appearance that they have buried their heads in the sand.

Ostriches typically eat plants, roots, and seeds but will also eat insects, lizards, or other creatures available in their sometimes harsh habitat.

Details:

Scientific classification

Kingdom : Animalia
Phylum : Chordata
Class : Aves
Infraclass : Palaeognathae
Order : Struthioniformes
Family : Struthionidae
Genus : Struthio

Ostriches are large flightless birds. Two living species are recognised; the common ostrich, native to large parts of Sub-Saharan Africa, and the Somali ostrich, native to the Horn of Africa.

They are the heaviest and largest living birds, with adult common ostriches weighing anywhere between 63.5 and 145 kilograms and laying the largest eggs of any living land animal. With the ability to run at 70 km/h (43.5 mph), they are the fastest birds on land. They are farmed worldwide, with significant industries in the Philippines and in Namibia. South Africa produces about 70% of global ostrich products, with the industry largely centered around the town of Oudtshoorn. Ostrich leather is a lucrative commodity, and the large feathers are used as plumes for the decoration of ceremonial headgear. Ostrich eggs and meat have been used by humans for millennia. Ostrich oil is another product that is made using ostrich fat.

Ostriches are of the genus Struthio in the order Struthioniformes, part of the infra-class Palaeognathae, a diverse group of flightless birds also known as ratites that includes the emus, rheas, cassowaries, kiwi and the extinct elephant birds and moa.

The common ostrich was historically native to the Arabian Peninsula, and ostriches were present across Asia as far east as China and Mongolia during the Late Pleistocene and possibly into the Holocene.

Taxonomic history

The genus Struthio was first described by Carl Linnaeus in 1758. The genus was used by Linnaeus and other early taxonomists to include the emu, rhea, and cassowary, until they each were placed in their own genera. The Somali ostrich (Struthio molybdophanes) has recently become recognized as a separate species by most authorities, while others are still reviewing the evidence.

Evolution

Struthionidae is a member of the Struthioniformes, a group of paleognath birds which first appeared during the Early Eocene, and includes a variety of flightless forms which were present across the Northern Hemisphere (Europe, Asia and North America) during the Eocene epoch. The closest relatives of Struthionidae within the Struthioniformes are the Ergilornithidae, known from the late Eocene to early Pliocene of Asia. It is therefore most likely that Struthionidae originated in Asia.

The earliest fossils of the genus Struthio are from the early Miocene ~21 million years ago of Namibia in Africa, so it is proposed that genus is of African origin. By the middle to late Miocene (5–13 mya) they had spread to and become widespread across Eurasia. While the relationship of the African fossil species is comparatively straightforward, many Asian species of ostrich have been described from fragmentary remains, and their interrelationships and how they relate to the African ostriches are confusing. In India, Mongolia and China, ostriches are known to have become extinct only around, or even after, the end of the last ice age; images of ostriches have been found prehistoric Chinese pottery and petroglyphs.

Distribution and habitat

Today, ostriches are only found natively in the wild in Africa, where they occur in a range of open arid and semi-arid habitats such as savannas and the Sahel, both north and south of the equatorial forest zone. The Somali ostrich occurs in the Horn of Africa, having evolved isolated from the common ostrich by the geographic barrier of the East African Rift. In some areas, the common ostrich's Masai subspecies occurs alongside the Somali ostrich, but they are kept from interbreeding by behavioral and ecological differences. The Arabian ostriches in Asia Minor and Arabia were hunted to extinction by the middle of the 20th century, and in Israel attempts to introduce North African ostriches to fill their ecological role have failed. Escaped common ostriches in Australia have established feral populations.

Species

In 2008, S. linxiaensis was transferred to the genus Orientornis. Three additional species, S. pannonicus, S. dmanisensis, and S. transcaucasicus, were transferred to the genus Pachystruthio in 2019. Several additional fossil forms are ichnotaxa (that is, classified according to the organism's trace fossils such as footprints rather than its body) and their association with those described from distinctive bones is contentious and in need of revision pending more good material.

Additional Information

Ostrich, (Struthio camelus), is a large flightless bird found only in open country in Africa. The largest living bird, an adult male may be 2.75 metres (about 9 feet) tall—almost half of its height is neck—and weigh more than 150 kg (330 pounds); the female is somewhat smaller. The ostrich’s egg, averaging about 150 mm (6 inches) in length by 125 mm (5 inches) in diameter and about 1.35 kg (3 pounds), is also the world’s largest. The male is mostly black but has white plumes in the wings and tail; females are mostly brown. The head and most of the neck, reddish to bluish in colour, is lightly downed; the legs, including the powerful thighs, are bare. The head is small, the bill short and rather wide; the big brown eyes have thick black lashes.

Ostriches are seen individually, in pairs, in small flocks, or in large aggregations, depending on the season. The ostrich relies on its strong legs—uniquely two-toed, with the main toe developed almost as a hoof—to escape its enemies, chiefly humans and the larger carnivores. A frightened ostrich can achieve a speed of 72.5 km (45 miles) per hour. If cornered, it can deliver dangerous kicks.

Ostriches live mainly on vegetation but also take some animal food, mainly insects; they can go without water for long periods. Breeding males emit lionlike roars and hisses as they fight for a harem of three to five hens. A communal nest scraped in the ground contains more than a dozen shiny, whitish eggs. The major hen of the harem may get rid of some of the eggs to make incubation more manageable. The male sits on the eggs by night; the females take turns during the day. The chicks hatch in about 40 days and when a month old can keep up with running adults. To escape detection, chicks as well as adults may lie on the ground with neck outstretched, a habit that may have given rise to the mistaken belief that the ostrich buries its head in the sand when danger threatens. Ostrich plumes adorned the helmets of medieval European knights, and in the 19th century such plumes were sold for women’s finery. This demand led to the establishment of ostrich farms in South Africa, the southern United States, Australia, and elsewhere, but the trade collapsed after World War I. Ostriches are now raised for their meat and hide, which provides a soft, fine-grained leather. The birds have been trained for saddle and sulky racing, but they tire easily and are not well suited for training. They do well in captivity and may live 50 years.

The ostrich is typical of a group of flightless birds called ratites. Ostrich populations differing slightly in skin colour, size, and egg features formerly were considered separate species, but now they are considered to be merely races of Struthio camelus. Most familiar is the North African ostrich, S. camelus camelus, ranging, in much-reduced numbers, from Morocco to Sudan. Ostriches also live in eastern and southern Africa. The Syrian ostrich (S. camelus syriacus) of Syria and Arabia became extinct in 1941. The ostrich is the only living species in the genus Struthio. Ostriches are the only members of the family Struthionidae in the order Struthioniformes—a group that also contains kiwis, emus, cassowaries, and rheas. The oldest fossil relatives of ostriches belong to the species Calciavis grandei, which were excavated from the Green River Formation in Wyoming and date to the Eocene Epoch, some 56 million to 34 million years ago.

eyJidWNrZXQiOiJjb250ZW50Lmhzd3N0YXRpYy5jb20iLCJrZXkiOiJnaWZcL29zdHJpY2guanBnIiwiZWRpdHMiOnsicmVzaXplIjp7IndpZHRoIjoyOTB9LCJ0b0Zvcm1hdCI6ImF2aWYifX0=

Jai Ganesh · Today 20:23:09

2384) Seahorse

Gist

The seahorse is a marine fish of the genus Hippocampus and family Syngnathidae, named for its horse-like head and upright posture, resembling a miniature horse in the sea. These bony fish have distinctive features such as a prehensile tail, independently moving eyes, and segmented bony armour, and they are found in shallow coastal waters worldwide.

Summary

A seahorse, (genus Hippocampus), any of about 50 species of marine fishes allied to pipefishes in the family Syngnathidae (order Gasterosteiformes). Seahorses are found in shallow coastal waters in latitudes from about 52° N to 45° S. Their habitats include coral reefs, mangroves, sea grass beds, and estuaries. They are unique in appearance, with their horselike head, prehensile tail, independently moving eyes, and brood pouch. They have long, tubular snouts and small, toothless mouths. Their bodies are covered with consecutive rings of bony plates. The name of the genus that contains seahorses is taken from the Greek words hippos (meaning “horse”) and kampos (meaning “sea monster”).

Seahorses vary in size, ranging in length from about 2 to 35 cm (about 0.8 to 14 inches). Adults of some of the smallest species—such as Denise’s pygmy seahorse (Hippocampus denise), found in the tropical western Pacific from Indonesia to Vanuatu, and Satomi’s pygmy seahorse (H. satomiae), found in the tropical Indian and Pacific Oceans from the Bay of Bengal to the Coral Sea—are less than 2 cm long. The largest species, the big-bellied seahorse (H. abdominalis), which inhabits the waters off South Australia and New Zealand, can grow up to 35 cm (13.8 inches) in length.

Seahorses are rather immobile, swimming more slowly than other fishes. When swimming they maintain a vertical position and propel themselves forward using a soft-rayed dorsal fin. They use pectoral fins located on the side of the head to maneuver. Some scientists contend that this upright swimming posture evolved shortly after the expansion of sea grasses in the western Pacific roughly 25 million years ago. These plants provided seahorses with useful hiding places to avoid enemies and to capture unsuspecting prey, and ancestors of the seahorse evolved to maximize the opportunities offered by this new habitat.

Seahorses are usually found clinging to plants or corals with their tails. Their sedentary habits coupled with excellent camouflage abilities render them successful ambush predators. When small organisms swim nearby, a seahorse may capture them by rapidly sucking them into the mouth. Seahorses also rely upon camouflage to avoid predators such as crabs and other fishes.

The reproductive behaviour of seahorses is notable in that the male carries the fertilized eggs. After an elaborate courtship, the female uses an ovipositor (egg duct) to place her eggs into a brood pouch located at the base of the male’s tail where the eggs are later fertilized. Depending on the species, the eggs remain in the pouch between 10 days and six weeks. During this time the male nurtures the developing young by regulating the chemistry of the fluid inside the pouch, slowly transforming it from that of his internal body fluids to that of salt water as pregnancy progresses. To nourish the growing young, the male also produces inorganic compounds and releases the hormone prolactin, which helps break down the proteins contributed by the female. Once the eggs hatch, the male convulses his body and expels the young through a single opening in the pouch. The young are miniature versions of their parents that receive no further care. The male can receive another brood of eggs almost immediately after giving birth. In some species a male and female will maintain a monogamous pair bond throughout the breeding season and produce many broods.

Commercially, seahorses are traded live as aquarium animals and dead for use in traditional medicines and as curios. Threatened by direct overfishing, accidental capture (bycatch) in other fisheries, and the destruction of their coastal habitats, some species—such as the Pacific seahorse (H. ingens)—face extinction.

Details:

Scientific classification

Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Syngnathiformes
Family: Syngnathidae
Subfamily: Hippocampinae
Genus: Hippocampus

A seahorse (also written sea-horse and sea horse) is any of 46 species of small marine bony fish in the genus Hippocampus. The genus name comes from the Ancient Greek hippókampos (ἱππόκαμπος), itself from híppos (ἵππος) meaning "horse" and kámpos meaning "sea monster" or "sea animal". Having a head and neck suggestive of a horse, seahorses also feature segmented bony armour, an upright posture and a curled prehensile tail. Along with the pipefishes and seadragons (Phycodurus and Phyllopteryx) they form the family Syngnathidae.

Evolution and fossil record

Anatomical evidence, supported by molecular, physical, and genetic evidence, demonstrates that seahorses are highly modified pipefish. The fossil record of seahorses, however, is very sparse. The best known and best studied fossils are specimens of Hippocampus guttulatus (though literature more commonly refers to them under the synonym of H. ramulosus), from the Marecchia River formation of Rimini Province, Italy, dating back to the Lower Pliocene, about 3 million years ago. The earliest known seahorse fossils are of two pipefish-like species, H. sarmaticus and H. slovenicus, from the coprolitic horizon of Tunjice Hills, a middle Miocene lagerstätte in Slovenia dating back about 13 million years.

Molecular dating implies that pipefish and seahorses diverged during the Late Oligocene. This has led to speculation that seahorses evolved in response to large areas of shallow water, newly created as the result of tectonic events. The shallow water would have allowed the expansion of seagrass habitats that served as camouflage for the seahorses' upright posture. These tectonic changes occurred in the western Pacific Ocean, pointing to an origin there, with molecular data suggesting two later, separate invasions of the Atlantic Ocean. In 2016, a study published in Nature found the seahorse genome to be the most rapidly evolving fish genome studied so far.

The evolution of seahorses from pipefish may have been an adaptation related to the biomechanics of prey capture. The unique posture of the seahorse allows them to capture small shrimps at larger distances than the pipefish is capable of.

Description

Seahorses range in size from 1.5 to 35 cm (0.6 to 13.8 in). They are named for their equine appearance, with bent necks and long snouted heads and a distinctive trunk and tail. Although they are bony fish, they do not have scales, but rather thin skin stretched over a series of bony plates, which are arranged in rings throughout their bodies. Each species has a distinct number of rings. The armor of bony plates also protects them against predators, and because of this outer skeleton, they no longer have ribs. Seahorses swim upright, propelling themselves using the dorsal fin, another characteristic not shared by their close pipefish relatives, which swim horizontally. Razorfish are the only other fish that swim vertically. The pectoral fins, located on either side of the head behind their eyes, are used for steering. They lack the caudal fin typical of fishes. Their prehensile tail is composed of square-like rings. They are adept at camouflage, and can grow and reabsorb spiny appendages depending on their habitat.

Unusual among fish, a seahorse has a flexible, well-defined neck. It also sports a crown-like spine or horn on its head, termed a "coronet", which is distinct for each species.

Seahorses swim extremely poorly, rapidly fluttering a dorsal fin and using pectoral fins to steer. The slowest-moving fish in the world is H. zosterae (the dwarf seahorse), with a top speed of about 1.5 m (5 ft) per hour. Since they are poor swimmers, they are most likely to be found resting with their prehensile tail wound around a stationary object. They have long snouts, which they use to drag up food, and their eyes can move independently of each other like those of a chameleon.

Habitat

Seahorses are mainly found in shallow tropical and temperate salt water throughout the world, from about 45°S to 45°N. They live in sheltered areas such as seagrass beds, estuaries, coral reefs, and mangroves. Four species are found in Pacific waters from North America to South America. In the Atlantic, Hippocampus erectus ranges from Nova Scotia to Uruguay. H. zosterae, known as the dwarf seahorse, is found in the Bahamas.

Colonies have been found in European waters such as the Thames Estuary.

Two species live in the Mediterranean Sea: H. guttulatus (the long-snouted seahorse), and H. hippocampus (the short-snouted seahorse). These species form territories; males stay within 1 sq m (10 sq ft) of habitat, while females range over about one hundred times that.

Feeding habits

Seahorses rely on stealth to ambush small prey such as copepods. They use pivot feeding to catch the copepod, which involves rotating their snout at high speed and then sucking in the copepod.
Seahorses use their long snouts to eat their food with ease. However, they are slow to consume their food and have extremely simple digestive systems that lack a stomach, so they must eat constantly to stay alive.[28] Seahorses are not very good swimmers, and for this reason they need to anchor themselves to seaweed, coral or anything else that will keep the seahorse in place. They do this by using their prehensile tails to grasp their object of choice. Seahorses feed on small crustaceans floating in the water or crawling on the bottom. With excellent camouflage, seahorses ambush prey that floats within striking range, sitting and waiting until an optimal moment. Mysid shrimp and other small crustaceans are favorites, but some seahorses have been observed eating other kinds of invertebrates and even larval fish. In a study of seahorses, the distinctive head morphology was found to give them a hydrodynamic advantage that creates minimal interference while approaching an evasive prey. Thus the seahorse can get very close to the copepods on which it preys. After successfully closing in on the prey without alerting it, the seahorse gives an upward thrust and rapidly rotates the head aided by large tendons that store and release elastic energy, to bring its long snout close to the prey. This step is crucial for prey capture, as oral suction only works at a close range. This two-phase prey capture mechanism is termed pivot-feeding. Seahorses have three distinctive feeding phases: preparatory, expansive, and recovery. During the preparatory phase, the seahorse slowly approaches the prey while in an upright position, after which it slowly flexes its head ventrally. In the expansive phase, the seahorse captures its prey by simultaneously elevating its head, expanding the buccal cavity, and sucking in the prey item. During the recovery phase, the jaws, head, and hyoid apparatus of the seahorse return to their original positions.

The amount of available cover influences the seahorse's feeding behaviour. For example, in wild areas with small amounts of vegetation, seahorses will sit and wait, but an environment with extensive vegetation will prompt the seahorse to inspect its environment, feeding while swimming rather than sitting and waiting. Conversely, in an aquarium setting with little vegetation, the seahorse will fully inspect its environment and makes no attempt to sit and wait.

Additional Information

Seahorses are members of the pipefish family. In addition to their iconic appearance, seahorses possess many interesting attributes. Among them are specialized structures in their skin cells, called chromatophores, which allow the mostly sessile seahorses to change color to mimic their surroundings. Well camouflaged as they cling to stalks of seagrass in their shallow habitats, seahorses can be hard to see.

Their truly remarkable biological claim to fame, however, is that male seahorses and sea dragons get pregnant and bear young—a unique adaptation in the animal kingdom.

After completing an elaborate courtship dance that may go on for hours or days, the female seahorse transfers her mature eggs into the male’s brood pouch, where they are fertilized. At the end of a gestation period usually lasting from two to four weeks, the pregnant male’s abdominal area begins to undulate rhythmically, and strong muscular contractions eject from a few dozen to as many as 1,000 fully formed baby seahorses into the surrounding water. After that, the offspring must fend for themselves. Large litters are necessary because only about 0.5 percent will survive to adulthood.

Many, if not all, of the 47 known seahorse species—14 of which were identified only in the 21st century—are in decline worldwide.

Because seahorses generally live in shallow, near-coastal waters, human activities including development, pollution, fisheries, and traditional medicine have reduced their numbers. At the same time, their universal appeal has worked against them; until recently, wild seahorses were often captured for the aquarium trade. The delicate creatures tend to fare poorly in aquaria, however. In recent years, captive-bred seahorses have shown promise as hardier tank-dwellers than their wild relatives.

Math Is Fun Forum

#2576 2025-08-27 19:19:38

Re: Miscellany

#2577 2025-08-28 17:59:13

Re: Miscellany

#2578 2025-09-02 20:18:55

Re: Miscellany

#2579 2025-09-03 16:53:36

Re: Miscellany

#2580 2025-09-04 14:33:58

Re: Miscellany

#2581 2025-09-05 18:12:25

Re: Miscellany

#2582 2025-09-06 22:44:37

Re: Miscellany

#2583 Yesterday 21:28:45

Re: Miscellany

#2584 Today 20:23:09

Re: Miscellany

Board footer