Giant mottled eel

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Giant mottled eel
Oounagi070224.jpg
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Anguilliformes
Family: Anguillidae
Genus: Anguilla
Species:
A. marmorata
Binomial name
Anguilla marmorata
Quoy and Gaimard, 1824
Synonyms
  • Anguilla fidjiensisGünther, 1870
  • Anguilla hildebrandtiPeters, 1881
  • Anguilla labrosaRichardson, 1848
  • Anguilla mauritianaBennett, 1831
  • Anguilla ohannaeGünther, 1867
  • Muraena manillensisBleeker, 1864

The giant mottled eel (Anguilla marmorata), also known as the marbled eel, is a species of tropical anguillid eel that is found in the Indo-Pacific and adjacent freshwater habitats. [2]

Contents

Description

Specimen Anguilla Marmorata, NOAA.jpg
Specimen

Similar to other anguillids, the giant mottled eel is cylindrical with small, well-developed pectoral fins and a protruding lower jaw. [3] The eel has thick, fleshy lips. [3] The eel has dorsal and anal fins that are continuous around the tail, with the origin of the dorsal-fin between the pectoral fins and anus. [3] It has small, oval-shaped scales that are embedded in the skin. [3]

Unlike some other anguillid species, this species has a mottled color. [2] [3] The adult eels are yellow with a greenish-brown to black marbling on their back and a white belly. [2] [3] The young elvers have less visible marbling and are grayish to yellow. [2] [3] The dorsal fin of the marbled eel is closer to the gill opening than to the anus, more anterior than other species of Anguilla . [3] Like all anguillid eels, it does not have pelvic fins. [4] The head is rounded and the snout is depressed. [4] Its teeth are small and in bands. [4] It has a total of 100 to 110 vertebrae. [2]

It can grow up to 2 meters (6.6 ft) for females and 1.5 meters (4.9 ft) for males and can weigh up to 20.5  kilograms (45 lb), [2] making it the largest species of anguillid eels. The marbled eel can live up to about 40 years. [3]

Distribution and habitat

This anguillid species can be found from East Africa to French Polynesia and as far north as southern Japan. [2] [3] [5] In Africa, it may be found within Mozambique and the lower Zambezi River. [2] The giant mottled eel has the widest distribution of all the Anguilla eels. [3] [6] It is usually found in tropical climates between 24°N to 33°S. [2] It has also been found in other more distant regions such as the Galapagos possibly due to abnormal larval transport associated with El Niño-Southern Oscillation events. [7] It is not on the IUCN Red List of Threatened Species, but in Taiwan, it is endangered. [3] [8]

In 2002, a single eel was captured from a pond close to Kaupo, Maui, Hawaii, though it is not indigenous to the area. [3]

Ecology and behaviour

Life cycle of eels Eel-life-circle1.svg
Life cycle of eels

The adults of this species are demersal, living on the bottom of fresh to brackish waters, in rivers, lakes, and tributaries. [2] This species and all anguillid eels are catadromous, migrating sometimes long distances out into the open ocean to spawning over deep water. [2] A spawning area of this species is known to be west of the Mariana Islands in an area of the North Equatorial Current in the western North Pacific, but other spawning areas are thought to exist in the western South Pacific and Indian Ocean. [9]

Marbled eels spend their adult lives in freshwater or estuarine habitats, and migrate to the ocean to reproduce. [3] When the eggs hatch, the leptocephali drift in ocean currents for months until they reach estuaries as glass eels where they migrate upstream into freshwater as elvers. [3] Then, after about 8 to 20 years in brackish or freshwater, the yellow eels grow up into silver eels (mature eels), and they return to the ocean for reproduction. [3]

Feeding

The marbled eel is carnivorous, but harmless, with a wide-ranging diet, eating shrimp, crabs, bony fish, and frogs. [10] It is nocturnal, so it is active at night. [10]

Significance to humans

Anguilla marmorata Stuffed specimen.jpg

Like other anguillid eels, this species is used as a source of food in some regions. [3] Some restaurants buy live eels. [3] In 1992, for example, a typical 12 kilogram (26.5 lb) marbled eel retailed for one thousand US dollars in China. [3] [11]

A giant mottled eel in the lagoon of Wallis island (South Pacific). Anguilla marmorata dans le lagon de Wallis pres de Nukufotu.jpg
A giant mottled eel in the lagoon of Wallis island (South Pacific).

An eel habitat, Cheonjiyeon Waterfalls' pond, is a natural monument in South Korea. [12]

Large individuals of this species are also highly regarded and are not harmed by native people in some island groups of the western Pacific.

Related Research Articles

<span class="mw-page-title-main">Fish migration</span> Movement of fishes from one part of a water body to another on a regular basis

Fish migration is mass relocation by fish from one area or body of water to another. Many types of fish migrate on a regular basis, on time scales ranging from daily to annually or longer, and over distances ranging from a few metres to thousands of kilometres. Such migrations are usually done for better feeding or to reproduce, but in other cases the reasons are unclear.

<span class="mw-page-title-main">European eel</span> Species of fish

The European eel is a species of eel. They are critically endangered due to hydroelectric dams, overfishing by fisheries on coasts for human consumption and parasites.

<span class="mw-page-title-main">American eel</span> Species of fish

The American eel is a facultative catadromous fish found on the eastern coast of North America. Freshwater eels are fish belonging to the elopomorph superorder, a group of phylogenetically ancient teleosts. The American eel has a slender, supple, snake-like body that is covered with a mucus layer, which makes the eel appear to be naked and slimy despite the presence of minute scales. A long dorsal fin runs from the middle of the back and is continuous with a similar ventral fin. Pelvic fins are absent, and relatively small pectoral fins can be found near the midline, followed by the head and gill covers. Variations exist in coloration, from olive green, brown shading to greenish-yellow and light gray or white on the belly. Eels from clear water are often lighter than those from dark, tannic acid streams.

<span class="mw-page-title-main">Eel life history</span> Eel life cycle

Eels are any of several long, thin, bony fishes of the order Anguilliformes. They have a catadromous life cycle, that is: at different stages of development migrating between inland waterways and the deep ocean. Because fishermen never caught anything they recognized as young eels, the life cycle of the eel was long a mystery. Of particular interest has been the search for the spawning grounds for the various species of eels, and identifying the population impacts of different stages of the life cycle.

<span class="mw-page-title-main">Short-finned eel</span> Species of fish

The short-finned eel, also known as the shortfin eel, is one of the 15 species of eel in the family Anguillidae. It is native to the lakes, dams and coastal rivers of south-eastern Australia, New Zealand, and much of the South Pacific, including New Caledonia, Norfolk Island, Lord Howe Island, Tahiti, and Fiji.

<span class="mw-page-title-main">Moray eel</span> Family of fishes

Moray eels, or Muraenidae, are a family of eels whose members are found worldwide. There are approximately 200 species in 15 genera which are almost exclusively marine, but several species are regularly seen in brackish water, and a few are found in fresh water.

<span class="mw-page-title-main">Ribbon eel</span> Species of fish

The ribbon eel, also known as the leaf-nosed moray eel or bernis eel, is a species of moray eel, the only member of the genus Rhinomuraena. The ribbon eel is found in sand burrows and reefs in the Indo-Pacific Ocean. Although generally placed in the moray eel family Muraenidae, it has several distinctive features leading some to place it in its own family, Rhinomuraenidae.

The Anguillidae are a family of ray-finned fish that contains the freshwater eels. Except from the genus Neoanguilla, with the only known species Neoanguilla nepalensis from Nepal, all the extant species and six subspecies in this family are in the genus Anguilla, and are elongated fish of snake-like bodies, with long dorsal, caudal and anal fins forming a continuous fringe. They are catadromous, spending their adult lives in freshwater, but migrating to the ocean to spawn.

<span class="mw-page-title-main">Arctic lamprey</span> Species of jawless fish

The Arctic lamprey, also known as the Japanese river lamprey or Japanese lampern, is a species of lamprey, a jawless fish in the order Petromyzontiformes. It inhabits coastal freshwater habitat types in the Arctic. Some populations are anadromous, spending part of their lives in the ocean. It is the most common and widespread lamprey in the Arctic region.

<span class="mw-page-title-main">New Zealand longfin eel</span> Species of fish

The New Zealand longfin eel, also known as ōrea, is a species of freshwater eel that is endemic to New Zealand. It is the largest freshwater eel in New Zealand and the only endemic species – the other eels found in New Zealand are the native shortfin eel, also found in Australia, and the naturally introduced Australian longfin eel. Longfin eels are long-lived, migrating to the Pacific Ocean near Tonga to breed at the end of their lives. They are good climbers as juveniles and so are found in streams and lakes a long way inland. An important traditional food source for Māori, who name them ōrea, longfin eel numbers are declining and they are classified as endangered, but over one hundred tonnes are still commercially fished each year.

<span class="mw-page-title-main">Speckled longfin eel</span> Species of fish

The speckled longfin eel, Australian long-finned eel or marbled eel is one of 15 species of eel in the family Anguillidae. It has a long snake-like cylindrical body with its dorsal, tail and anal fins joined to form one long fin. It usually has a brownish green or olive green back and sides with small darker spots or blotches all over its body. Its underside is paler. It has a small gill opening on each side of its wide head, with thick lips. It is Australia's largest freshwater eel, and the female usually grows much larger than the male. It is also known as the spotted eel.

<i>Anguilla bengalensis bengalensis</i> Subspecies of fish

Anguilla bengalensis bengalensis, the Indian mottled eel, is a subspecies of eel in the genus Anguilla of the family Anguillidae. It is found throughout the Indian subcontinent and neighbouring regions including the East Indies.

<i>Anguilla bengalensis</i> Species of fish

The mottled eel, also known as the African mottled eel, the Indian longfin eel, the Indian mottled eel, the long-finned eel or the river eel, is a demersal, catadromous eel in the family Anguillidae. It was described by John McClelland in 1844. It is a tropical, freshwater eel which is known from East Africa, Bangladesh, Andaman Islands, Mozambique, Malawi, Sri Lanka, Sumatra, and Indonesia and recently from Madagascar. The eels spend most of their lives in freshwater at a depth range of 3–10 metres, but migrate to the Indian Ocean to breed. Males can reach a maximum total length of 121 centimetres and a maximum weight of 7,000 grams. The eels feed primarily off of benthic crustaceans, mollusks, finfish and worms.

<span class="mw-page-title-main">Japanese eel</span> Species of fish

The Japanese eel is a species of anguillid eel found in Japan, Korea, Taiwan, China, and Vietnam, as well as the northern Philippines. Like all the eels of the genus Anguilla and the family Anguillidae, it is catadromous, meaning it spawns in the sea but lives parts of its life in freshwater. Raised in aquaculture ponds in most countries, the Japanese eel makes up 95% of the commercially sold eel in Japan, the other 5% is shipped over by air to the country from Europe. This food in Japan is called unagi; they are an essential part of the food culture, with many restaurants serving grilled eel called kabayaki. However, presumably due to a combination of overfishing and habitat loss or changing water conditions in the ocean interfering with spawning and the transport of their leptocephali this species is endangered.

<span class="mw-page-title-main">Eel</span> Order of fishes

Eels are ray-finned fish belonging to the order Anguilliformes, which consists of eight suborders, 20 families, 164 genera, and about 1000 species. Eels undergo considerable development from the early larval stage to the eventual adult stage and are usually predators.

The Philippine mottled eel is an eel in the family Anguillidae. It was described by Shun Watanabe, Jun Aoyama, and Katsumi Tsukamoto in 2009. It is a tropical eel known from the Pinacanauan River system on Luzon Island, in the Philippines. The eels spend most of their lives in freshwater but migrate to the ocean to breed.

The Pacific shortfinned eel, also known as the Pacific shortfinned freshwater eel, the short-finned eel, and the South Pacific eel, is an eel in the family Anguillidae. It was described by Albert Günther in 1871. It is a tropical, freshwater eel which is known from western New Guinea, Queensland, Australia, the Society Islands, and possibly South Africa. The eels spend most of their lives in freshwater, but migrate to the Pacific Ocean to breed. Males can reach a maximum total length of 110 centimetres, but more commonly reach a TL of around 60 cm. The Pacific shortfinned eel is most similar to Anguilla australis, and Anguilla bicolor, but can be distinguished by the number of vertebrae.

<span class="mw-page-title-main">Juvenile fish</span> Young fish

Fish go through various life stages between fertilization and adulthood. The life of fish start as spawned eggs which hatch into immotile larvae. These larval hatchlings are not yet capable of feeding themselves and carry a yolk sac which provides stored nutrition. Before the yolk sac completely disappears, the young fish must mature enough to be able to forage independently. When they have developed to the point where they are capable of feeding by themselves, the fish are called fry. When, in addition, they have developed scales and working fins, the transition to a juvenile fish is complete and it is called a fingerling, so called as they are typically about the size of human fingers. The juvenile stage lasts until the fish is fully grown, sexually mature and interacting with other adult fish.

Marbled eel is a common name for several fishes; while it most commonly refers to Anguilla marmorata, it may also refer to:

Cyvirus anguillidallo1, also known as Anguillid herpesvirus 1 (AngHV-1) is a species of virus in the genus Cyprinivirus, family Alloherpesviridae, and order Herpesvirales.

References

  1. Pike, C.; Crook, V.; Jacoby, D.; Gollock, M. (2020). "Anguilla marmorata". IUCN Red List of Threatened Species . 2020: e.T166189A176493885. doi: 10.2305/IUCN.UK.2020-3.RLTS.T166189A176493885.en . Retrieved 20 November 2021.
  2. 1 2 3 4 5 6 7 8 9 10 11 Froese, Rainer; Pauly, Daniel (eds.) (2006). "Anguilla marmorata" in FishBase . February 2006 version.
  3. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 USGS. "Anguilla marmorata (fact sheet)". Archived from the original on 2009-05-10. Retrieved 2006-11-21.
  4. 1 2 3 Discover Life. "Anguilla marmorata" . Retrieved 2011-06-28.
  5. Tsukamoto, K.; Aoyama, J. (1998). "Evolution of freshwater eels of the genus Anguilla: a probable scenario". Environmental Biology of Fishes. 52 (1–3): 139–148. Bibcode:1998EnvBF..52..139T. doi:10.1023/A:1007427724175.
  6. Robinet, T.; Guyet, S.; Marquet, G. R.; Mounaix, B. A.; Olivier, J. M.; Tsukamoto, K.; Valade, P.; Feunteun, E. (2003). "Elver invasion, population structure and growth of marbled eels Anguilla marmorata in a tropical river on Réunion Island in the Indian Ocean". Environmental Biology of Fishes. 68 (4): 339–348. Bibcode:2003EnvBF..68..339R. doi:10.1023/B:EBFI.0000005761.51686.f7.
  7. McCosker, J. E.; Bustamante, R. H. & Wellington, G. M. (2003). "The freshwater eel, Anguilla marmorata, discovered at Galapagos" (PDF). Noticias de Galápagos. 62: 2–6. Retrieved 21 June 2011.
  8. Shiao, J. C.; Iizuka, Y.; Chang, C. W.; Tzeng, W. N. (2003). "Disparities in habitat use and migratory behavior between tropical eel Anguilla marmorata and temperate eel A. japonica in four Taiwanese rivers" (PDF). Marine Ecology Progress Series. 261: 233–242. Bibcode:2003MEPS..261..233S. doi: 10.3354/meps261233 .
  9. Miller, M.; Mochioka, N.; Otake, T.; Tsukamoto, K. (2002). "Evidence of a spawning area of Anguilla marmorata in the western North Pacific". Marine Biology. 140 (4): 809–814. Bibcode:2002MarBi.140..809M. doi:10.1007/s00227-001-0754-9.
  10. 1 2 Paul Harvey Skelton (10 September 2001). A complete guide to the freshwater fishes of Southern Africa. Struik. p. 108. ISBN   978-1-86872-643-1 . Retrieved 23 June 2011.[ permanent dead link ]
  11. Williamson, Gordon R.; Boëtius, Jan (1993). "The eels Anguilla marmorata and A. japonica in the Pearl River, China, and Hong Kong". Asian Fisheries Science. 6 (2): 129–138. doi:10.33997/j.afs.1993.6.2.001.
  12. Lee, Cecilia Hae-Jin. (2008). Frommer's South Korea . Hoboken, NJ: Wiley. pp.  392. ISBN   978-0-470-18191-1.