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  • Snow Leopard

    The snow leopard (Panthera uncia) is a species of large cat in the genus Panthera of the family Felidae. The species is native to the mountain ranges of Central and South Asia. It is listed as Vulnerable on the IUCN Red List because the global population is estimated to number fewer than 10,000 mature individuals and is expected to decline about 10% by 2040. It is mainly threatened by poaching and habitat destruction following infrastructural developments. It inhabits alpine and subalpine zones at elevations of 3,000–4,500 m (9,800–14,800 ft), ranging from eastern Afghanistan, the Himalayas and the Tibetan Plateau to southern SiberiaMongolia and western China. In the northern part of its range, it also lives at lower elevations.

    Taxonomically, the snow leopard was long classified in the monotypic genus Uncia. Since phylogenetic studies revealed the relationships among Panthera species, it has since been considered a member of that genus. Two subspecies were described based on morphological differences, but genetic differences between the two have not yet been confirmed. It is therefore regarded as a monotypic species. The species is widely depicted in Kyrgyz culture.

    Naming and etymology

    Illustration of an ‘Ounce’ (1658)

    The Old French word once, which was intended to be used for the Eurasian lynx (Lynx lynx), is where the Latin name uncia and the English word ounce both originate. Once is believed to have originated from a previous form of the word lynx through a process known as false splitting. The word once was originally considered to be pronounced as l’once, where l’ stands for the elided form of the word la (‘the’) in French. Once was then understood to be the name of the animal.[2] The word panther derives from the classical Latin panthēra, itself from the ancient Greek πάνθηρ pánthēr, which was used for spotted cats.[3]

    Taxonomy

    Snow leopard skull in the collection of the Museum Wiesbaden

    Felis uncia was the scientific name used by Johann Christian Daniel von Schreber in 1777 who described a snow leopard based on an earlier description by Georges-Louis Leclerc, Comte de Buffon, assuming that the cat occurred along the Barbary Coast, in PersiaEast India and China.[4] The genus name Uncia was proposed by John Edward Gray in 1854 for Asian cats with a long and thick tail.[5] Felis irbis, proposed by Christian Gottfried Ehrenberg in 1830, was a skin of a female snow leopard collected in the Altai Mountains. He also clarified that several leopard (P. pardus) skins were previously misidentified as snow leopard skins.[6] Felis uncioides proposed by Thomas Horsfield in 1855 was a snow leopard skin from Nepal in the collection of the Museum of the East India Company.[7]

    Uncia uncia was used by Reginald Innes Pocock in 1930 when he reviewed skins and skulls of Panthera species from Asia. He also described morphological differences between snow leopard and leopard skins.[8] Panthera baikalensis-romanii proposed by a Russian scientist in 2000 was a dark brown snow leopard skin from the Petrovsk-Zabaykalsky District in southern Transbaikal.[9]

    The snow leopard was long classified in the monotypic genus Uncia.[10] They were subordinated to the genus Panthera based on results of phylogenetic studies.[11][12][13][14]

    Until spring 2017, there was no evidence available for the recognition of subspecies. Results of a phylogeographic analysis indicate that three subspecies should be recognised:[15]

    • P. u. uncia in the range countries of the Pamir Mountains
    • P. u. irbis in Mongolia, and
    • P. u. uncioides in the Himalayas and Qinghai.

    This view has been both contested and supported by different researchers.[16][17][18][19]

    Two possible European paleosubspecies have been named in the 2020s, Panthera uncia pyrenaica from France and Panthera uncia lusitana from Portugal, but the subspecific validity of the former is uncertain.[20]

    Evolution

    Two cladograms proposed for Panthera. The upper cladogram is based on two studies published in 2006 and 2009,[11][21] the lower one is based on studies published in 2010 and 2011.[12][22]

    Based on the phylogenetic analysis of the DNA sequence sampled across the living Felidae, the snow leopard forms a sister group with the tiger (P. tigris). The genetic divergence time of this group is estimated at 4.62 to 1.82 million years ago.[11][21] The snow leopard and the tiger probably diverged between 3.7 to 2.7 million years ago.[12] Panthera originates most likely in northern Central Asia. Panthera blytheae excavated in western Tibet’s Ngari Prefecture has been initially described the oldest known Panthera species and exhibits skull characteristics similar to the snow leopard,[23] though its taxonomic placement has been disputed by other researchers who suggest that the species likely belongs to a different genus.[24][25] The mitochondrial genomes of the snow leopard, the leopard and the lion (P. leo) are more similar to each other than their nuclear genomes, indicating that their ancestors hybridised at some point in their evolution.[26]

    The earliest known definitive record of the modern snow leopard is dated to the Late Pleistocene based on a specimen discovered from the Niuyan Cave of China. A Middle Pleistocene specimen from the Zhoukoudian Peking Man Site which is similar to the modern snow leopard has been referred to as P. aff. uncia.[20] Putative fossils of the snow leopard found in the Pabbi Hills of Pakistan were dated to the Early Pleistocene,[27] but the fossils might instead represent a leopard or belong to the genus Puma.[28]

    It has also been suggested that the snow leopard had European paleosubspecies during the Pleistocene epoch. Panthera uncia pyrenaica was described in 2022 based on fossil material found in France that was dated to the early Middle Pleistocene around 0.57 to 0.53 million years ago.[28] Panthera uncia lusitana was described in 2025 based on fossil material discovered from Late Pleistocene strata in Portugal, and the describers of P. u. lusitana assigned P. u. pyrenaica outside the modern snow leopard as P. pyrenaica due to the lack of similar traits, though it might represent a basal related species.[20]

    Characteristics

    Showing canines

    Thickly furred tail

    The snow leopard’s fur is whitish to grey with black spots on the head and neck, with larger rosettes on the back, flanks and bushy tail. Its muzzle is short, its forehead domed, and its nasal cavities are large. The fur is thick with hairs measuring 5 to 12 cm (2.0 to 4.7 in) in length, and its underbelly is whitish. They are stocky, short-legged, and slightly smaller than other cats of the genus Panthera, reaching a shoulder height of 56 cm (22 in), and ranging in head to body size from 75 to 150 cm (30 to 59 in). Its tail is 80 to 105 cm (31 to 41 in) long.[29] Males average 45 to 55 kg (99 to 121 lb), and females 35 to 40 kg (77 to 88 lb).[30] Occasionally, large males reaching 75 kg (165 lb) have been recorded, and small females under 25 kg (55 lb).[31] Its canine teeth are 28.6 mm (1.13 in) long and are more slender than those of the other Panthera species.[32]

    The snow leopard shows several adaptations for living in cold, mountainous environments. Its small rounded ears help to minimize heat loss, and its broad paws effectively distribute the body weight for walking on snow. Fur on the undersides of the paws enhances its grip on steep and unstable surfaces, and helps to minimize heat loss. Its long and flexible tail helps the cat to balance in rocky terrain. The tail is very thick due to fat storage, and is covered in a thick layer of fur, which allows the cat to use it like a blanket to protect its face when asleep.[33]

    The snow leopard differs from the other Panthera species by a shorter muzzle, an elevated forehead, a vertical chin and a less developed posterior process of the lower jaw.[8] Despite its partly ossified hyoid bone, a snow leopard cannot roar, as its 9 mm (0.35 in) short vocal folds provide little resistance to airflow.[34][35] Its nasal openings are large in relation to the length of its skull and width of its palate; thanks to their size the volume of air inhaled with each breath is optimised, and the cold dry air becomes warmer.[36] It is not especially adapted to high-altitude hypoxia.[37]

    Distribution and habitat

    The snow leopard is distributed from the west of Lake Baikal through southern Siberia, in the Kunlun Mountains, Altai Mountains, Sayan and Tannu-Ola Mountains, in the Tian Shan, through TajikistanKyrgyzstanUzbekistan and Kazakhstan to the Hindu Kush in eastern Afghanistan, Karakoram in northern Pakistan, in the Pamir Mountains, the Tibetan Plateau and in the high elevations of the Himalayas in IndiaNepal and Bhutan. In Mongolia, they inhabit the Mongolian and Gobi Altai Mountains and the Khangai Mountains. In Tibet, they occur up to the Altyn-Tagh in the north.[30][38] They inhabit alpine and subalpine zones at elevations of 3,000 to 4,500 m (9,800 to 14,800 ft), but also lives at lower elevations in the northern part of their range.[39]

    Potential snow leopard habitat in the Indian Himalayas is estimated at less than 90,000 km2 (35,000 sq mi) in Jammu and KashmirLadakhUttarakhandHimachal PradeshSikkim and Arunachal Pradesh, of which about 34,000 km2 (13,000 sq mi) is considered good habitat, and 14.4% is protected. In the beginning of the 1990s, the Indian snow leopard population was estimated at 200–600 individuals living across about 25 protected areas.[38] The Snow Leopard Population Assessment in India (SPAI) Programme counted the number of snow leopards between 2019 and 2023 and found their number to be 718, with 477 in Ladakh, 124 in Uttarakhand, 51 in Himachal Pradesh, 36 in Arunachal Pradesh, 21 in Sikkim, and nine in Jammu and Kashmir.[40]

    In summer, the snow leopard usually lives above the tree line on alpine meadows and in rocky regions at elevations of 2,700 to 6,000 m (8,900 to 19,700 ft). In winter, they descend to elevations around 1,200 to 2,000 m (3,900 to 6,600 ft). They prefer rocky, broken terrain, and can move in 85 cm (33 in) deep snow, but prefers to use existing trails made by other animals.[31]

    Snow leopards were recorded by camera traps at 16 locations in northeastern Afghanistan’s isolated Wakhan Corridor.[41]

    Behavior and ecology

    Scent rubbing
    Walking on snow

    The snow leopard’s vocalizations include meowing, grunting, prusten and moaning. They can purr when exhaling.[29]

    It is solitary and mostly active at dawn till early morning, and again in afternoons and early evenings. They mostly rest near cliffs and ridges that provide vantage points and shade. In Nepal’s Shey Phoksundo National Park, the home ranges of five adult radio-collared snow leopards largely overlapped, though they rarely met. Their individual home ranges ranged from 12 to 39 km2 (4.6 to 15.1 sq mi). Males moved between 0.5 and 5.45 km (0.31 and 3.39 mi) per day, and females between 0.2 and 2.25 km (0.12 and 1.40 mi), measured in straight lines between survey points. Since they often zigzagged in the precipitous terrain, they actually moved up to 7 km (4.3 mi) in a single night.[42] Up to 10 individuals inhabit an area of 100 km2 (39 sq mi); in habitats with sparse prey, an area of 1,000 km2 (390 sq mi) usually supports only five individuals.[43]

    A study in the Gobi Desert from 2008 to 2014 revealed that adult males used a mean home range of 144–270 km2 (56–104 sq mi), while adult females ranged in areas of 83–165 km2 (32–64 sq mi). Their home ranges overlapped less than 20%. These results indicate that about 40% of the 170 protected areas in their range countries are smaller than the home range of a single male snow leopard.[44]

    Snow leopards leave scent marks to indicate their territories and common travel routes. They scrape the ground with the hind feet before depositing urine or feces, but also spray urine onto rocks.[31] Their urine contains many characteristic low molecular weight compounds with diverse functional groups including pentanolhexanolheptanol3-octanonenonanal and indole, which possibly play a role in chemical communication.[45]

    Hunting and diet

    Snow leopard with a gray marmot in Kyrgyzstan

    The snow leopard is a carnivore and actively hunts its prey. Its preferred wild prey species are Himalayan blue sheep (Pseudois nayaur), Himalayan tahr (Hemitragus jemlahicus), argali (Ovis ammon), markhor (Capra falconeri) and wild goat (C. aegagrus). It also preys on domestic livestock.[46][47] It prefers prey ranging in weight from 36 to 76 kg (79 to 168 lb), but also hunts smaller mammals such as Himalayan marmot (Marmota himalayana), pika and vole species. Its diet depends on prey availability and varies across its range and season. In the Himalayas, it preys mostly on Himalayan blue sheep, Siberian ibex (C. sibirica), white-bellied musk deer (Moschus leucogaster) and wild boar (Sus scrofa). In the KarakoramTian Shan, Altai and Mongolia’s Tost Mountains, its main prey consists of Siberian ibex, Thorold’s deer (Cervus albirostris), Siberian roe deer (Capreolus pygargus) and argali.[48][49] Snow leopard feces collected in northern Pakistan also contained remains of rhesus macaque (Macaca mulatta), masked palm civet (Paguma larvata), Cape hare (Lepus capensis), house mouse (Mus musculus), Kashmir field mouse (Apodemus rusiges), grey dwarf hamster (Cricetulus migratorius) and Turkestan rat (Rattus pyctoris).[50] In 2017, a snow leopard was photographed carrying a freshly killed woolly flying squirrel (Eupetaurus cinereus) near Gangotri National Park.[51] In Mongolia, domestic sheep comprises less than 20% of its diet, although wild prey has been reduced and interactions with people are common.[49] It is capable of killing most ungulates in its habitat, with the probable exception of the adult male wild yak. It also eats grass and twigs.[31]

    The snow leopard actively pursues prey down steep mountainsides, using the momentum of its initial leap to chase animals for up to 300 m (980 ft). Then it drags the prey to a safe location and consumes all edible parts of the carcass. It can survive on a single Himalayan blue sheep for two weeks before hunting again, and one adult individual apparently needs 20–30 adult blue sheep per year.[1][31] Snow leopards have been recorded to hunt successfully in pairs, especially mating pairs.[52]

    The snow leopard is easily driven away from livestock and readily abandons kills, often without defending itself.[31] Only two attacks on humans have been reported, both near Almaty in Kazakhstan, and neither were fatal. In 1940, a rabid snow leopard attacked two men; and an old, toothless emaciated individual attacked a person passing by.[53][54]

    Reproduction and life cycle

    Cubs at the Cat Survival Trust in Welwyn

    Female with her cub in Zurich Zoo

    Snow leopards become sexually mature at two to three years, and normally live for 15–18 years in the wild. In captivity they can live for up to 25 years. Oestrus typically lasts five to eight days, and males tend not to seek out another partner after mating, probably because the short mating season does not allow sufficient time. Paired snow leopards mate in the usual felid posture, from 12 to 36 times a day. They are unusual among large cats in that they have a well-defined birth peak. They usually mate in late winter, marked by a noticeable increase in marking and calling. Females have a gestation period of 90–100 days, and the cubs are born between April and June.[31] A litter usually consists of two to three cubs, in exceptional cases there can be up to seven.[53]

    The female gives birth in a rocky den or crevice lined with fur shed from her underside. The cubs are born blind and helpless, although already with a thick coat of fur, and weigh 320 to 567 g (11.3 to 20.0 oz). Their eyes open at around seven days, and the cubs can walk at five weeks and are fully weaned by 10 weeks. The cubs leave the den when they are around two to four months of age.[31] Three radio-collared snow leopards in Mongolia’s Tost Mountains gave birth between late April and late June. Two female cubs started to part from their mothers at the age of 20 to 21 months, but reunited with them several times for a few days over a period of 4–7 months. One male cub separated from his mother at the age of about 22 months, but stayed in her vicinity for a month and moved out of his natal range at 23 months of age.[55]

    The snow leopard has a generation length of eight years.[56]

    Threats

    Major threats to the population include poaching and illegal trade of its skins and body parts.[1] Between 1999 and 2002, three live snow leopard cubs and 16 skins were confiscated, 330 traps were destroyed and 110 poachers were arrested in Kyrgyzstan. Undercover operations in the country revealed an illegal trade network with links to Russia and China via Kazakhstan. The major skin trade center in the region is the city of Kashgar in Xinjiang.[57] In Tibet and Mongolia, skins are used for traditional dresses, and meat in traditional Tibetan medicine to cure kidney problems; bones are used in traditional Chinese and Mongolian medicine for treating rheumatism, injuries and pain of human bones and tendons. Between 1996 and 2002, 37 skins were found in wildlife markets and tourist shops in Mongolia.[58] Between 2003 and 2016, 710 skins were traded, of which 288 skins were confiscated. In China, an estimated 103 to 236 animals are poached every year, in Mongolia between 34 and 53, in Pakistan between 23 and 53, in India from 21 to 45, and in Tajikistan 20 to 25. In 2016, a survey of Chinese websites revealed 15 advertisements for 44 snow leopard products; the dealers offered skins, canine teeth, claws and a tongue.[59] In September 2014, nine snow leopard skins were found during a market survey in Afghanistan.[60]

    Greenhouse gas emissions will likely cause a shift of the treeline in the Himalayas and a shrinking of the alpine zone, which may reduce snow leopard habitat by an estimated 30%.[61]

    Where snow leopards prey on domestic livestock, they are subject to human–wildlife conflict.[1] The loss of natural prey due to overgrazing by livestock, poaching, and defense of livestock are the major drivers for the ever decreasing snow leopard population.[31] Livestock also cause habitat degradation, which, alongside the increasing use of forests for fuel, reduces snow leopard habitat.[62]

    Conservation

    CountryYearEstimate
    Afghanistan201650–200[63]
    Bhutan2023134[64]
    China20164,500[65]
    India2024718[66]
    Kazakhstan2016100–120[67]
    Kyrgyzstan2016300–400[68]
    Mongolia20161,000[69]
    Nepal2016301–400[70]
    Pakistan2016250–420[71]
    Russia201670–90[72]
    Tajikistan2016250–280[73]
    Uzbekistan201630–120[74]

    The snow leopard is listed in CITES Appendix I.[30] They have been listed as threatened with extinction in Schedule I of the Convention on the Conservation of Migratory Species of Wild Animals since 1985.[58] Hunting snow leopards has been prohibited in Kyrgyzstan since the 1950s.[57] In India, the snow leopard is granted the highest level of protection under the Wildlife Protection Act, 1972, and hunting is sentenced with imprisonment of 3–7 years.[75] In Nepal, they have been legally protected since 1973, with penalties of 5–15 years in prison and a fine for poaching and trading them.[76] Since 1978, they have been listed in the Soviet Union’s Red Book and is still inscribed today in the Red Data Book of the Russian Federation as threatened with extinction. Hunting snow leopards is only permitted for the purposes of conservation and monitoring, and to eliminate a threat to the life of humans and livestock. Smuggling of snow leopard body parts is punished with imprisonment and a fine.[77] Hunting snow leopards has been prohibited in Afghanistan since 1986.[60] In China, they have been protected by law since 1989; hunting and trading snow leopards or their body parts constitute a criminal offence that is punishable by the confiscation of property, a fine and a sentence of at least 10 years in prison.[78] They have been protected in Bhutan since 1995.[79]

    At the end of 2020, 35 cameras were installed on the outskirts of Almaty, Kazakhstan in hopes to catch footage of snow leopards. In November 2021, it was announced by the Russian World Wildlife Fund (WWF) that snow leopards were spotted 65 times on these cameras in the Trans-Ili Alatau mountains since the cameras were installed.[80][44][81][82][83]

    Global Snow Leopard Forum

    In 2013, government leaders and officials from all 12 countries encompassing the snow leopard’s range (Afghanistan, Bhutan, China, India, Kazakhstan, Kyrgyzstan, Mongolia, Nepal, Pakistan, Russia, Tajikistan, and Uzbekistan) came together at the Global Snow Leopard Forum (GSLF) initiated by the then-President of Kyrgyzstan Almazbek Atambayev, and the State Agency on Environmental Protection and Forestry under the government of Kyrgyzstan. The meeting was held in Bishkek, and all countries agreed that the snow leopard and the high mountain habitat need trans-boundary support to ensure a viable future for snow leopard populations, and to safeguard its fragile environment. The event brought together many partners, including NGOs like the Snow Leopard Conservancy, the Snow Leopard Trust, and the Nature and Biodiversity Conservation Union. Also supporting the initiative were the Snow Leopard Network, the World Bank‘s Global Tiger Initiative, the United Nations Development Programme, the World Wild Fund for Nature, the United States Agency for International Development, and Global Environment Facility.[84]

    In captivity

    Snow leopard in the San Diego Zoo

    The Moscow Zoo exhibited the first captive snow leopard in 1872 that had been caught in Turkestan. In Kyrgyzstan, 420 live snow leopards were caught between 1936 and 1988 and exported to zoos around the world. The Bronx Zoo housed a live snow leopard in 1903; this was the first ever specimen exhibited in a North American zoo.[85] The first captive bred snow leopard cubs were born in the 1990s in the Beijing Zoo.[57] The Snow Leopard Species Survival Plan was initiated in 1984; by 1986, American zoos held 234 individuals.[86][87]

    Cultural significance

    Snow leopard on the reverse of the old 10,000-Kazakhstani tenge banknote
    Emblem of Tatarstan, depicting the Aq Bars, a mythical winged Snow leopard

    The snow leopard is widely used in heraldry and as an emblem in Central Asia. The Aq Bars (‘White Leopard’) is a political symbol of the TatarsKazakhs, and Bulgars. A mythical winged Aq Bars is depicted on the national coat of arms of Tatarstan, the seal of the city of Samarqand, Uzbekistan and the old coat of arms of Astana. A snow leopard is depicted on the official seal of Almaty and on the former 10,000 Kazakhstani tenge banknote. In Kyrgyzstan, it is used in highly stylized form in the modern emblem of the capital Bishkek, and the same art has been integrated into the badge of the Kyrgyzstan Girl Scouts Association. It is also considered to be a sacred creature by the Kyrgyz people. A crowned snow leopard features in the arms of Shushensky District in Russia. It is the state animal of Ladakh and Himachal Pradesh in India.[88][89]

    The 1978 book The Snow Leopard is an account by Peter Matthiessen about his two-month journey through the Dolpo region of the Nepal Himalayas in search of the snow leopard.

  • Seahorses

    This article is about the genus of fish. For the creature in mythology, see Hippocampus (mythology). For the structure of the brain, see Hippocampus. For other uses, see Seahorse (disambiguation).

    Seahorses
    Temporal range: Lower Miocene to present – 23–0 Ma PreꞒOSDCPTJKPgN
    Short-snouted seahorse (Hippocampus hippocampus)
    Scientific classification
    Domain:Eukaryota
    Kingdom:Animalia
    Phylum:Chordata
    Class:Actinopterygii
    Order:Syngnathiformes
    Family:Syngnathidae
    Subfamily:Hippocampinae
    Genus:Hippocampus
    Rafinesque, 1810[1][2]
    Type species
    Syngnathus hippocampus
    Linnaeus, 1758
    Species
    see Species.
    Synonyms
    Acentronura Kaup, 1853Farlapiscis Whitley, 1931[3]Jamsus Ginsburg, 1937Macleayina Fowler, 1907Phyllopteryx Swainson 1839

    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 (κάμπος) meaning “sea monster”[4][5] or “sea animal”.[6] Having a head and neck suggestive of a horse, seahorses also feature segmented bony armour, an upright posture and a curled prehensile tail.[7] Along with the pipefishes and seadragons (Phycodurus and Phyllopteryx) they form the family Syngnathidae.

    Habitat

    [edit]

    Seahorses are mainly found in shallow tropical and temperate salt water throughout the world, from about 45°S to 45°N.[8] They live in sheltered areas such as seagrass beds, estuariescoral 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 UruguayH. zosterae, known as the dwarf seahorse, is found in the Bahamas.

    Colonies have been found in European waters such as the Thames Estuary.[9]

    Two species live in the Mediterranean SeaH. guttulatus (the long-snouted seahorse), H. hippocampus (the short-snouted seahorse).[10][11] These species form territories; males stay within 1 m2 (10 sq ft) of habitat, while females range over about one hundred times that.[12]

    Description

    [edit]

    Spiny seahorse H. histrix from East Timor holding on to soft coral with its prehensile tail
    H. jayakari

    Seahorses range in size from 1.5 to 35 cm (0.6 to 13.8 in).[13] 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.[14] The armor of bony plates also protects them against predators,[15] and because of this outer skeleton, they no longer have ribs.[16] 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 that can be unlocked only in the most extreme conditions.[17] They are adept at camouflage, and can grow and reabsorb spiny appendages depending on their habitat.[18]

    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.[19]

    Seahorses swim very 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.[20] 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 suck up food, and their eyes can move independently of each other like those of a chameleon.[21]

    Evolution and fossil record

    [edit]

    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 3million 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 13million years.[22]

    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.[23] 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.[24] In 2016, a study published in Nature found the seahorse genome to be the most rapidly evolving fish genome studied so far.[25]

    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.[26]

    Reproduction

    [edit]

    See also: Animal sexual behavior § Seahorse

    Seahorse life-cycle

    The male seahorse is equipped with a brood pouch on the ventral, or front-facing, side of the tail. When mating, the female seahorse deposits up to 1,500 eggs in the male’s pouch. The male carries the eggs for 9 to 45 days until the seahorses emerge fully developed, but very small. The young are then released into the water, and the male often mates again within hours or days during the breeding season.[27]

    Courtship

    [edit]

    Before breeding, seahorses may court for several days. Scientists believe the courtship behavior synchronizes the animals’ movements and reproductive states, so that the male can receive the eggs when the female is ready to deposit them. During this time, they may change color, swim side by side holding tails or grip the same strand of sea grass with their tails, and wheel around in unison in what is known as a “predawn dance”. They eventually engage in a “true courtship dance” lasting about 8 hours, during which the male pumps water through the egg pouch on his trunk which expands and opens to display its emptiness. When the female’s eggs reach maturity, she and her mate let go of any anchors and drift upward snout-to-snout, out of the sea grass, often spiraling as they rise. They interact for about 6 minutes, reminiscent of courtship.[28] The female inserts her ovipositor into the male’s brood pouch and deposits dozens to thousands of eggs. As the female releases her eggs, her body slims while his swells. Both animals then sink back into the sea grass and she swims away.[28]

    Phases of courtship

    [edit]

    Seahorses exhibit four phases of courtship that are indicated by clear behavioral changes and changes in the intensity of the courtship act. Phase 1, the initial courtship phase, typically takes place in the early morning one or two days before physical copulation. During this phase the potential mates brighten in colour, quiver, and display rapid side-to-side body vibrations. These displays are performed alternately by both the male and the female seahorse. The following phases, 2 through 4, happen sequentially on the day of copulation. Phase 2 is marked by the female pointing, a behaviour in which the female will raise her head to form an oblique angle with her body. In phase 3 males will also begin the same pointing behaviour in response to the female. Finally, the male and female will repeatedly rise upward together in a water column and end in mid-water copulation, in which the female will transfer her eggs directly into the male’s brood pouch.[29]

    Phase 1: Initial courtship

    [edit]

    This initial courtship behaviour takes place about 30 minutes after dawn on each courtship day, until the day of copulation. During this phase the males and females will remain apart during the night, but after dawn they will come together in a side-by-side position, brighten, and engage in courtship behaviour for about 2 to 38 minutes. There is repeated reciprocal quivering. This starts when the male approaches the female, brightens and begins to quiver. The female will follow the male with her own display, in which she will also brighten and quiver about 5 seconds later. As the male quivers, he will rotate his body towards the female who will then rotate her body away. During phase 1 the tails of both seahorses are positioned within 1 cm of each other on the same hold-fast and both of their bodies are angled slightly outward from the point of attachment. However, the female will shift her tail attachment site, causing the pair to circle their common hold-fast.[29]

    Phase 2: Pointing and pumping

    [edit]

    This phase begins with the female beginning her pointing posture, by leaning her body towards the male, who will simultaneously lean away and quiver. This phase can last up to 54 minutes. Following phase 2 is a latency period (typically between 30 minutes and four hours), during which the seahorses display no courtship behaviour and females are not bright; males will usually display a pumping motion with their body.[29]

    Phase 3: Pointing – pointing

    [edit]

    Seahorses in Phase 2 of courtship

    The third phase begins with the females brightening and assuming the pointing position. The males respond with their own brightening and pointing display. This phase ends with the male departing. It usually lasts nine minutes and can occur one to six times during courtship.[29]

    Phase 4: Rising and copulation

    [edit]

    The final courtship phase includes 5–8 bouts of courtship. Each bout of courtship begins with both the male and female anchored to the same plant about 3 cm apart; usually they are facing each other and are still bright in colour from the previous phase. During the first bout, following the facing behaviour, the seahorses will rise upward together anywhere from 2 to 13 cm in a water column. During the final rise, the female will insert her ovipositor and transfer her eggs through an opening into the male’s brood pouch.[29]

    Fertilization

    [edit]

    During fertilization in Hippocampus kuda, the brood pouch was found to be open for only six seconds while egg deposition occurred. During this time seawater entered the pouch where the spermatozoa and eggs meet in a seawater milieu. This hyperosmotic environment facilitates sperm activation and motility. The fertilization is therefore regarded as being physiologically ‘external’ within a physically ‘internal’ environment after the closure of the pouch.[30] It is believed that this protected form of fertilization reduces sperm competition among males. Within the Syngnathidae (pipefishes and seahorses) protected fertilization has not been documented in the pipefishes but the lack of any distinct differences in the relation of testes size to body size suggests that pipefishes may also have evolved mechanisms for more efficient fertilization with reduced sperm competition.[31]

    Gestation

    [edit]

    Seahorses in Phase 4 of courtship

    The fertilized eggs are then embedded in the pouch wall and become surrounded by a spongy tissue.[32] The pouch provides oxygen,[33] as well as a controlled environment incubator. Though the egg yolk contributes nourishment to the developing embryo, the male sea horses contribute additional nutrients such as energy-rich lipids and also calcium to allow them to build their skeletal system, by secreting them into the brood pouch that are absorbed by the embryos. Further they also offer immunological protection, osmoregulation, gas exchange and waste transport.[34]

    The eggs then hatch in the pouch, where the salinity of the water is regulated; this prepares the newborns for life in the sea.[28][35][36]

    Birth

    [edit]

    The number of young released by the male seahorse averages 100–1000 for most species, but may be as low as 5 for the smaller species, or as high as 2,500.[32] When the fry are ready to be born, the male expels them with muscular contractions. He typically gives birth at night and is ready for the next batch of eggs by morning when his mate returns. Like almost all other fish species, seahorses do not nurture their young after birth. Infants are susceptible to predators or ocean currents which wash them away from feeding grounds or into temperatures too extreme for their delicate bodies. Less than 0.5% of infants survive to adulthood, explaining why litters are so large. These survival rates are actually fairly high compared to other fish, because of their protected gestation, making the process worth the great cost to the father. The eggs of most other fish are abandoned immediately after fertilization.[36]

    Reproductive roles

    [edit]

    Diagram of a pregnant male seahorse (Hippocampus comes)[25]
    Pregnant male seahorse at the New York Aquarium

    Reproduction is energetically costly to the male. This brings into question why the sexual role reversal even takes place. In an environment where one partner incurs more energy costs than the other, Bateman’s principle suggests that the lesser contributor takes the role of the aggressor. Male seahorses are more aggressive and sometimes fight for female attention. According to Amanda Vincent of Project Seahorse, only males tail-wrestle and snap their heads at each other. This discovery prompted further study of energy costs. To estimate the female’s direct contribution, researchers chemically analyzed the energy stored in each egg. To measure the burden on the males, oxygen consumption was used. By the end of incubation, the male consumed almost 33% more oxygen than before mating. The study concluded that the female’s energy expenditure while generating eggs is twice that of males during incubation, confirming the standard hypothesis.[28]

    Why the male seahorse (and other members of the Syngnathidae) carries the offspring through gestation is unknown, though some researchers believe it allows for shorter birthing intervals, in turn resulting in more offspring.[37] Given an unlimited number of ready and willing partners, males have the potential to produce 17% more offspring than females in a breeding season. Also, females have “time-outs” from the reproductive cycle 1.2 times longer than those of males. This seems to be based on mate choice, rather than physiology. When the female’s eggs are ready, she must lay them in a few hours or eject them into the water column. Making eggs is a huge cost to her physically, since they amount to about a third of her body weight. To protect against losing a clutch, the female demands a long courtship. The daily greetings help to cement the bond between the pair.[38]

    Monogamy

    [edit]

    Though seahorses are not known to mate for life, many species form pair bonds that last through at least the breeding season. Some species show a higher level of mate fidelity than others.[39][40] However, many species readily switch mates when the opportunity arises. H. abdominalis and H. breviceps have been shown to breed in groups, showing no continuous mate preference. Many more species’ mating habits have not been studied, so it is unknown how many species are actually monogamous, or how long those bonds actually last.[41]

    Although monogamy within fish is not common, it does appear to exist for some. In this case, the mate-guarding hypothesis may be an explanation. This hypothesis states, “males remain with a single female because of ecological factors that make male parental care and protection of offspring especially advantageous.”[42] Because the rates of survival for newborn seahorses are so low, incubation is essential. Though not proven, males could have taken on this role because of the lengthy period the females require to produce their eggs. If males incubate while females prepare the next clutch (amounting to a third of body weight), they can reduce the interval between clutches.[citation needed]

    Feeding habits

    [edit]

    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.[43]

    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.[44] Seahorses are not very good swimmers, and for this reason they need to anchor themselves to seaweedcoral or anything else that will keep the seahorse in place. They do this by using their prehensile tails to grasp their object of choice.[45] 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.[44] 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.[43][46] 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.[46][47] 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.[48]

    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.[49]

    Seahorse hiding using camouflage
    Seahorses (Hippocampus erectus) at the New England Aquarium

    Threats of extinction

    [edit]

    Because data is lacking on the sizes of the various seahorse populations, as well as other issues including how many seahorses are dying each year, how many are being born, and the number used for souvenirs, there is insufficient information to assess their risk of extinction, and the risk of losing more seahorses remains a concern. Coral reefs and seagrass beds are deteriorating, reducing viable habitats for seahorses.[50] Additionally, bycatch in many areas causes high cumulative effects on seahorses, with an estimated 37 million individuals being removed annually over 21 countries.[51]

    Aquaria

    [edit]

    This section needs additional citations for verification. Please help improve this article by adding citations to reliable sources in this section. Unsourced material may be challenged and removed.
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    While many aquarium hobbyists keep them as pets, seahorses collected from the wild tend to fare poorly in home aquaria. Many eat only live foods such as brine shrimp and are prone to stress, which damages their immune systems and makes them susceptible to disease.[52]

    In recent years, however, captive breeding has become more popular. Such seahorses survive better in captivity, and are less likely to carry diseases. They eat frozen mysidacea (crustaceans) that are readily available from aquarium stores,[53] and do not experience the stress of moving out of the wild. Although captive-bred seahorses are more expensive, they take no toll on wild populations.

    Seahorses should be kept in an aquarium with low flow and placid tank mates. They are slow feeders, so fast, aggressive feeders will leave them without food.[53] Seahorses can coexist with many species of shrimp and other bottom-feeding creatures. Gobies also make good tank-mates. Keepers are generally advised to avoid eelstangstriggerfishsquidoctopus, and sea anemones.[54]

    Water quality is very important for the survival of seahorses in an aquarium. They are delicate species which should not be added to a new tank. The water parameters are recommended to be as follows although these fish may acclimatise to different water over time:

    • Temperature: 23–28 °C (73–82 °F)
    • pH: 8.1–8.4
    • Ammonia: 0 mg/L (0 ppm) (0.01 mg/L (0.01 ppm) may be tolerated for short periods)
    • Nitrite: 0 mg/L (0 ppm) (0.125 mg/L (0.125 ppm) may be tolerated for short periods)
    • S.G.: 1.021–1.024 at 23–24 °C (73–75 °F)[citation needed]

    A water-quality problem will affect fish behaviour and can be shown by clamped fins, reduced feeding, erratic swimming, and gasping at the surface.[55] Seahorses require vertical swimming space to perform reproductive functions and to prevent depth-related health conditions like gas bubble disease, so a refugium that is at least 20 inches by 51 centimeters deep is recommended inside an aquarium.[56]

    Animals sold as “freshwater seahorses” are usually the closely related pipefish, of which a few species live in the lower reaches of rivers. The supposed true “freshwater seahorse” called H. aimei is not a valid species, but a synonym sometimes used for Barbour’s and hedgehog seahorses. The latter, which is often confused with the former, can be found in estuarine environments, but is not actually a freshwater fish.[57]

    Consumption

    [edit]

    Dried seahorse
    Seahorse and scorpion skewers as street food

    Seahorse populations are thought to be endangered as a result of overfishing and habitat destruction. Despite a lack of scientific studies or clinical trials,[58][59] the consumption of seahorses is widespread in traditional Chinese medicine, primarily in connection with impotence, wheezing, nocturnal enuresis, and pain, as well as labor induction.[60] Up to 20 million seahorses may be caught each year to be sold for such uses.[61] Preferred species of seahorses include H. kellogiiH. histrixH. kudaH. trimaculatus, and H. mohnikei.[60] Seahorses are also consumed by Indonesians, central Filipinos, and many other ethnic groups.[citation needed]

    Import and export of seahorses has been controlled under CITES since 15 May 2004. However, Indonesia, Japan, Norway, and South Korea have chosen to opt out of the trade rules set by CITES.

    The problem may be exacerbated by the growth of pills and capsules as the preferred method of ingesting seahorses. Pills are cheaper and more available than traditional, individually tailored prescriptions of whole seahorses, but the contents are harder to track. Seahorses once had to be of a certain size and quality before they were accepted by TCM practitioners and consumers. Declining availability of the preferred large, pale, and smooth seahorses has been offset by the shift towards prepackaged preparations, which makes it possible for TCM merchants to sell previously unused, or otherwise undesirable juvenile, spiny, and dark-coloured animals. Dried seahorse retails from US$600 to $3000 per kilogram, with larger, paler, and smoother animals commanding the highest prices. In terms of value based on weight, seahorses retail for more than the price of silver and almost that of gold in Asia.[62]

    Conservation

    [edit]

    Seahorses are iconic and charismatic animals whose conservation is of global concern.[63] Preserving seahorses’ varied habitats, including seagrass beds (such as Posidonia oceanica and Zostera marina), mangroves, coral reefs, estuaries, seaweeds, and all the creatures that inhabit them, is closely related to protecting seahorses. Owing to their widespread use in collective imagery, these fish are popular wildlife viewing destinations, frequently serve as flagship species for international conservation campaigns, and are especially good at attracting public engagement in community scientific projects. According to Woodall et al.,[64] these creatures are susceptible to anthropogenic activities such as habitat degradation brought on by residential, commercial, and touristic coastal development, as well as accidental bycatch from damaging fishing equipment like dredges and trawls. There is little ecological data on seahorses because of their low population, seemingly dispersed location, and cryptic behavior.[65] Because of all these traits, seahorses are especially difficult to survey, assess, and monitor in order to enhance their conservation status. Conservation of these fishes depends on an understanding of their threats, distribution, and preferred habitats, which necessitates a thorough understanding of their regional ranges.[66] Finding hotspots and possible hazards, as well as confirming their existence, actually depends on getting a good resolution of their presence and movement to carry out maps on their distribution.[66] Maps can be used to assess future seahorse datasets and to pinpoint regions of study interest where more information can be gathered about the presence, quantity, habitat choice, influence of human activities, and status of seahorses.[66]

    Species

    [edit]

    On the basis of the newest overall taxonomic review[67] of the genus Hippocampus with further new species and partial taxonomic review,[68][69][70][71] the number of recognized species in this genus is considered to be 46 (retrieved May 2020):

    H. kuda, known as the “common seahorse”
    H. subelongatus, known as the “West Australian seahorse”
    H. whitei, known as “White’s seahorse”

    Pygmy seahorses

    [edit]

    Hippocampus satomiae (Satomi’s pygmy seahorse) attached to coral

    Main article: Hippocampinae

    Pygmy seahorses are those members of the genus that are less than 15 mm (916 in) tall and 17 mm (1116 in) wide. Previously the term was applied exclusively to the species H. bargibanti but since 1997, discoveries have made this usage obsolete. The species H. minotaurH. deniseH. colemaniH. pontohiH. severnsiH. satomiaeH. waleananusH. naluH. japapigu have been described. Other species that are believed to be unclassified have also been reported in books, dive magazines and on the Internet. They can be distinguished from other species of seahorse by their 12 trunk rings, low number of tail rings (26–29), the location in which young are brooded in the trunk region of males and their extremely small size.[74] Molecular analysis (of ribosomal RNA) of 32 Hippocampus species found that H. bargibanti belongs in a separate clade from other members of the genus and therefore that the species diverged from the other species in the ancient past.[24]

    Most pygmy seahorses are well camouflaged and live in close association with other organisms including colonial hydrozoans (Lytocarpus and Antennellopsis), coralline algae (Halimeda), and sea fans (MuricellaAnnella, and Acanthogorgia). This combined with their small size accounts for why most species have only been noticed and classified since 2001.