''Monognathus'', or onejaw, is the only genus of the family Monognathidae of deep-sea eels. The name comes from the Greek ''monos'' meaning “one” and ''gnathos'' meaning “jaw”, a reference to the large mouth in comparison with the rest of the fish, and also the absence of an upper jaw ( maxilla and premaxilla bones are absent).

Description

The dorsal and

anal fin Fins are distinctive anatomical features composed of bony spines or rays protruding from the body of a fish. They are covered with skin and joined together either in a webbed fashion, as seen in most bony fish, or similar to a flipper, as se ...

s lack bony supports and the pectoral fins are missing. The snout has a fang connected to glands, which are venomous in adults. These eels are virtually blind, with rudimentary eyes and small olfactory organs, although the male olfactory organs are enlarged, perhaps suggesting a method of "sniffing out" a mate. Typical lengths are from 4 to 10 cm (1.5–4 in), the maximum length recorded is 15.9 cm (6.3 in).

Distribution

They are found at depths of over 2,000 m (6,600 ft), and are found in all oceans.

Species

The fifteen known species are: * ''

Monognathus ahlstromi ''Monognathus ahlstromi'', the paddletail onejaw, is an ocean-dwelling eel found in the North Pacific Ocean off of the coast of the United States. It is found up to a depth of 2,000 m.

Raju The Raju are a Telugu caste found mostly in the Indian state of Andhra Pradesh. Varna Status The Raju caste, which A. Satyanarayana calls the "locally dominant landed gentry", claims Kshatriya status in the varna system despite there being ...

, 1974 (Paddletail onejaw) * ''

Monognathus berteli ''Monognathus'', or onejaw, is the only genus of the family Monognathidae of deep-sea eels. The name comes from the Greek ''monos'' meaning “one” and ''gnathos'' meaning “jaw”, a reference to the large mouth in comparison with the rest o ...

'' J. G. Nielsen & Hartel, 1996. * ''

Monognathus bertini ''Monognathus'', or onejaw, is the only genus of the family Monognathidae of deep-sea eels. The name comes from the Greek ''monos'' meaning “one” and ''gnathos'' meaning “jaw”, a reference to the large mouth in comparison with the rest o ...

'' Bertelsen & J. G. Nielsen, 1987. * ''

Monognathus boehlkei ''Monognathus boehlkei'' is a deep-sea eel inhabiting all oceans at depths up to 2,000 meters. Little is known of this species. Description The species is characterized by a distinctive high number of anal fin rays and a short, blunt head with ...

'' Bertelsen & J. G. Nielsen, 1987. * ''

Monognathus bruuni ''Monognathus'', or onejaw, is the only genus of the family Monognathidae of deep-sea eels. The name comes from the Greek ''monos'' meaning “one” and ''gnathos'' meaning “jaw”, a reference to the large mouth in comparison with the rest o ...

Bertin Bertin ( la, Bertinus; 615 – ''c''. 709 AD), also known as Saint Bertin the Great, was the Franks, Frankish abbot of a monastery in Saint-Omer later named the Abbey of Saint Bertin after him. He is venerated as a saint by the Catholic and Ort ...

, 1936. * ''

Monognathus herringi ''Monognathus'', or onejaw, is the only genus of the family Monognathidae of deep-sea eels. The name comes from the Greek ''monos'' meaning “one” and ''gnathos'' meaning “jaw”, a reference to the large mouth in comparison with the rest o ...

'' Bertelsen & J. G. Nielsen, 1987. * ''

Monognathus isaacsi ''Monognathus'', or onejaw, is the only genus of the family Monognathidae of deep-sea eels. The name comes from the Greek ''monos'' meaning “one” and ''gnathos'' meaning “jaw”, a reference to the large mouth in comparison with the rest o ...

, 1974. * ''

Monognathus jesperseni ''Monognathus'', or onejaw, is the only genus of the family Monognathidae of deep-sea eels. The name comes from the Greek ''monos'' meaning “one” and ''gnathos'' meaning “jaw”, a reference to the large mouth in comparison with the rest o ...

, 1936. * ''

Monognathus jesse ''Monognathus'', or onejaw, is the only genus of the family Monognathidae of deep-sea eels. The name comes from the Greek ''monos'' meaning “one” and ''gnathos'' meaning “jaw”, a reference to the large mouth in comparison with the rest o ...

, 1974. * ''

Monognathus nigeli ''Monognathus'', or onejaw, is the only genus of the family Monognathidae of deep-sea eels. The name comes from the Greek ''monos'' meaning “one” and ''gnathos'' meaning “jaw”, a reference to the large mouth in comparison with the rest o ...

'' Bertelsen & J. G. Nielsen, 1987. * ''

Monognathus ozawai ''Monognathus'', or onejaw, is the only genus of the family Monognathidae of deep-sea eels. The name comes from the Greek ''monos'' meaning “one” and ''gnathos'' meaning “jaw”, a reference to the large mouth in comparison with the rest o ...

'' Bertelsen & J. G. Nielsen, 1987. * ''

Monognathus rajui ''Monognathus'', or onejaw, is the only genus of the family Monognathidae of deep-sea eels. The name comes from the Greek ''monos'' meaning “one” and ''gnathos'' meaning “jaw”, a reference to the large mouth in comparison with the rest o ...

'' Bertelsen & J. G. Nielsen, 1987. * ''

Monognathus rosenblatti ''Monognathus'', or onejaw, is the only genus of the family Monognathidae of deep-sea eels. The name comes from the Greek ''monos'' meaning “one” and ''gnathos'' meaning “jaw”, a reference to the large mouth in comparison with the rest o ...

'' Bertelsen & J. G. Nielsen, 1987. * ''

Monognathus smithi ''Monognathus'', or onejaw, is the only genus of the family Monognathidae of deep-sea eels. The name comes from the Greek ''monos'' meaning “one” and ''gnathos'' meaning “jaw”, a reference to the large mouth in comparison with the rest o ...

'' Bertelsen & J. G. Nielsen, 1987. * ''

Monognathus taningi ''Monognathus'', or onejaw, is the only genus of the family Monognathidae of deep-sea eels. The name comes from the Greek ''monos'' meaning “one” and ''gnathos'' meaning “jaw”, a reference to the large mouth in comparison with the rest o ...

, 1936.

References

Monognathidae Deep sea fish Marine fish genera Taxa named by Léon Bertin {{Saccopharyngiformes-stub