''Congriscus megastomus'' is an

eel Eels are ray-finned fish belonging to the order Anguilliformes (), which consists of eight suborders, 19 families, 111 genera, and about 800 species. Eels undergo considerable development from the early larval stage to the eventual adult stage ...

in the family

Congridae The Congridae are the family of conger and garden eels. Congers are valuable and often large food fishes, while garden eels live in colonies, all protruding from the sea floor after the manner of plants in a garden (thus the name). The family i ...

(conger/garden eels).''Congriscus megastomus''
at www.fishbase.org. It was described by

Albert Günther Albert Karl Ludwig Gotthilf Günther Fellow of the Royal Society, FRS, also Albert Charles Lewis Gotthilf Günther (3 October 1830 – 1 February 1914), was a German-born British zoologist, ichthyologist, and herpetologist. Günther is ranked th ...

in 1877, originally under the genus '' Congromuraena''.Günther, A., 1877 (1 Nov.)

ef. 2009 EF or ef may refer to: Arts and entertainment * Ef (band), a post-rock band from Sweden * '' Ef: A Fairy Tale of the Two.'', a Japanese adult visual novel series by Minori, or its anime adaptations Businesses and organizations * Eagle Forum, an ...

''Preliminary notes on new fishes collected in Japan during the expedition of H. M. S. ''Challenger.''.'' Annals and Magazine of Natural History (Series 4) v. 20 (no. 119) (art. 56): 433-446. It is a

marine Marine is an adjective meaning of or pertaining to the sea or ocean. Marine or marines may refer to: Ocean * Maritime (disambiguation) * Marine art * Marine biology * Marine debris * Marine habitats * Marine life * Marine pollution Military * ...

temperate In geography, the temperate climates of Earth occur in the middle latitudes (23.5° to 66.5° N/S of Equator), which span between the tropics and the polar regions of Earth. These zones generally have wider temperature ranges throughout t ...

-water dwelling eel which is known from Japan and the Kyushu–Palau Ridge, in the northwestern Pacific Ocean. It inhabits

reef A reef is a ridge or shoal of rock, coral or similar relatively stable material, lying beneath the surface of a natural body of water. Many reefs result from natural, abiotic component, abiotic processes—deposition (geology), deposition of ...

s. Males can reach a maximum

total length Fish measurement is the measuring of individual fish and various parts of their anatomies. These data are used in many areas of ichthyology, including taxonomy and fisheries biology. Overall length * Standard length (SL) is the length of a fish ...

of 40 centimeters. This species' remarkably large and distinct

leptocephalus Leptocephalus (meaning "slim head") is the flat and transparent larva of the eel, marine eels, and other members of the superorder Elopomorpha. This is one of the most diverse groups of teleosts, containing 801 species in 4 orders, 24 famili ...

larvae were previously known under the name ''Thalassenchelys coheni.'' In 2016, scientists used genetic techniques to link the larvae to the adult ''C. megastomus.'' These larvae reach a maximum size of and have a number of unusual characteristics, including two forward-facing front teeth that may be used for feeding on different prey than other eel larvae. ''Congriscus megastomus'' is preyed on by '' Chlorophthalmus albatrossis''. Its own diet includes

finfish Fish are aquatic, craniate, gill-bearing animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish as well as various extinct related groups. Approximately 95% of l ...

such as ''

Diaphus coeruleus ''Diaphus'' is a genus of lanternfish Lanternfishes (or myctophids, from the Greek μυκτήρ ''myktḗr'', "nose" and ''ophis'', "serpent") are small mesopelagic fish of the large family Myctophidae. One of two families in the order Mycto ...

'', ''

Diaphus sagamiensis ''Diaphus sagamiensis'' is a species of lanternfish found in the north-western Pacific Ocean. Etymology The fish is named after Sagami Bay, Japan. References Myctophidae Taxa named by Charles Henry Gilbert Fish described in 1913 ...

'', ''

Hymenocephalus lethonemus ''Hymenocephalus lethonemus'' is a species of rattail. It occurs at depths of up to 485 m (1591 ft) in the waters off southern Japan, the Philippines and northern Taiwan. This is a small, slender rattail with a total length of up to ...

'', ''

Synagrops japonicus ''Synagrops japonicus'' is a species of fish within the family of Acropomatidae. It was described by Döderlein in 1883. Distribution It can be found from Eastern Africa up to the islands of Hawaii. Most of them live at a depth of 100-800 m ...

'', and species of '' Macrura'', as well as

euphausiid Krill are small crustaceans of the order Euphausiacea, and are found in all the world's oceans. The name "krill" comes from the Norwegian word ', meaning "small fry of fish", which is also often attributed to species of fish. Krill are consi ...

plankton crustaceans and

polychaetes Polychaeta () is a paraphyletic class of generally marine annelid worms, commonly called bristle worms or polychaetes (). Each body segment has a pair of fleshy protrusions called parapodia that bear many bristles, called chaetae, which are ...

.Food items reported for ''Congriscus megastomus''
at www.fishbase.org.

References

Congridae Fish described in 1877 Taxa named by Albert Günther {{Anguilliformes-stub