Leptocephalus is a genus that was used for species of larval eels, called leptocephali, that were thought to be new fish species, or whose adult eel species were not known. Leptocephali differ so much in appearance from their adults that the larvae and adults of eels are not easily matched, and when first discovered, leptocephali were thought to be a distinct type of fishes, but not eels. Because of this, the genus designation of Leptocephalus was used for a while for unidentified leptocephali even after it was known that these were the larvae of eels thus becoming a "wastebasket taxon", but this practice is no longer used. Examples of marine congrid larvae, found in the western Indian Ocean and the Red Sea that were named this way are listed below. Only two species in two families are currently treated as having any validity, though the validity of L. bellottii is strongly in doubt.
Rhynchoconger is a genus of eels in the family Congridae.
The sea conger, also known as the big-eye conger, is an eel in the family Congridae. It was described by Pieter Bleeker in 1853, originally under the genus Conger. It is a tropical, marine eel which is known from the western Pacific Ocean, including Kanagawa Prefecture, Japan; the eastern China Sea, and the East Indies. It leads a benthic lifestyle and dwells in sand and mud. Males can reach a maximum total length of 51 centimeters.
The Lord Howe conger is an eel in the family Congridae. It was described by Allan Riverstone McCulloch and Edgar Ravenswood Waite in 1916, originally under the genus Congermuraena. It is a marine, deep water-dwelling eel which is known from the western Pacific Ocean, including northeastern Australia, New Caledonia, and the South Fiji Basin. It is known to dwell at a depth range of 60–600 metres. Females can reach a maximum total length of 42.2 centimetres.
The blunt-tooth conger is an eel in the family Congridae. It was described by Paul Pappenheim in 1914, originally under the genus Leptocephalus. It is a marine, deep-water dwelling eel which is known from the Indo-West Pacific, including the Red Sea, eastern Africa, and Australia. It is known to dwell at a depth range of 360–800 metres. Males can reach a maximum total length of 30 centimetres.
Conger erebennus is an eel in the family Congridae. It was described by David Starr Jordan and John Otterbein Snyder in 1901, originally under the genus Leptocephalus. It is a marine, temperate water-dwelling eel which is known from Japan and the Korean Peninsula, in the northwestern Pacific Ocean. It is also called the "anaconda" アナコンダ in Tokyo, Japan.
Gnathophis capensis, the Southern Atlantic conger or southern conger, is an eel in the family Congridae. It was described by Johann Jakob Kaup in 1856, originally under the genus Leptocephalus. It is a subtropical, marine eel which is known from the southeastern Atlantic Ocean, including from False Bay to Plettenberg Bay, South Africa and also on Tristan da Cunha Island. It is known to dwell at a depth of 100 metres. Males can reach a maximum total length of 37 cm.
Gnathophis longicauda, the little conger, little conger eel or silver conger, is an eel in the family Congridae. It was described by Edward Pierson Ramsay and James Douglas Ogilby in 1888, originally under the genus Congromuraena. It is a marine, temperate water-dwelling eel which is endemic to Australia, in the Indo-West Pacific. It dwells at a depth range of 2–99 metres, and inhabits the continental shelf and slope.
Gnathophis microps, the smalleye conger, is an eel in the family Congridae. It was described by Emma Stanislavovna Karmovskaya and John Richard Paxton in 2000. It is a marine, deep water-dwelling eel which is known from western Australia, in the eastern Indian Ocean. It dwells at a depth range of 200–320 metres.
Gnathophis mystax, the thinlip conger or blacktailed conger, is an eel in the family Congridae. It was described by François Étienne Delaroche in 1809, originally under the genus Muraena. It is a subtropical, marine eel which is known from the eastern Atlantic Ocean, including southern Portugal, the Mediterranean, and Morocco. It dwells at a depth range of 75–800 metres, and inhabits mud and sand on the continental slope. Males can reach a maximum total length of 60 centimetres, but more commonly reach a TL of 35 centimetres.
Gnathophis nasutus is an eel in the family Congridae. It was described by Emma Stanislavovna Karmovskaya and John Richard Paxton in 2000. It is a tropical, marine eel which is known from western Australia, in the eastern Indian Ocean. It dwells at a depth range of 80–140 metres.
Gnathophis xenica is an eel in the family Congridae. It was described by Kiyomatsu Matsubara and Akira Ochiai in 1951, originally as a subspecies of Arisoma nystromi. It is a marine, temperate water-dwelling eel which is known from Japan, in the northwestern Pacific Ocean. Males can reach a maximum total length of 32 centimeters.
The Rubbernose conger is an eel in the family Congridae. It was described by Johnson T. F. Chen and Herman Ting-Chen Weng in 1967, originally under the genus Rhynchoconger. It is a marine, tropical eel which is known from the western Pacific Ocean, including Taiwan and Australia. It dwells at a depth range of 280 to 440 metres. Males can reach a maximum total length of 36.7 centimetres (1.20 ft).
The yellow conger is an eel in the family Congridae. It was described by George Brown Goode and Tarleton Hoffman Bean in 1896. It is a marine, tropical eel which is known from the Gulf of Mexico and the mouth of the Amazon River, in the western Atlantic Ocean. It dwells at a depth range of 26 to 183 meters, and inhabits soft sediments. Males can reach a maximum total length of 150 centimeters (59 in), but more commonly reach a TL of 30 centimeters (12 in).
The whiptail conger, also known as the conger eel in Cuba, is an eel in the family Congridae. It was described by Isaac Ginsburg in 1951, originally under the genus Congrina. It is a marine, deep water-dwelling eel which is known from the western Atlantic Ocean, including the United States in the northern Gulf of Mexico and northern South America. It is known to dwell at a depth of 203 meters (666 ft). Males can reach a maximum total length of 61 centimeters (24 in).
Rhynchoconger guppyi is an eel in the family Congridae. It was described by John Roxborough Norman in 1925, originally under the genus Congromuraena. It is a marine, tropical eel which is known from the western central Atlantic Ocean, including the Gulf of Mexico, the Caribbean, northern South America and southern Brazil. It dwells at a depth range of 137 to 458 metres, and inhabits the continental slope. Males can reach a maximum total length of 95 centimetres (37 in).
The bignose conger is an eel in the family Congridae. It was described by David Starr Jordan and Charles Harvey Bollman in 1890. It is a tropical, marine eel which is known from the eastern central and southeastern Pacific Ocean, including Chile, Colombia, Costa Rica, Ecuador, El Salvador, Guatemala, Honduras, Mexico, Nicaragua, Panama, and Peru. It dwells at a depth range of 25–90 metres. Males can reach a maximum total length of 40 centimetres, but more commonly reach a TL of 30 cm.
Rhynchoconger squaliceps is an eel in the family Congridae. It was described by Alfred William Alcock in 1894, originally under the genus Congromuraena. It is a marine, tropical eel which is known from the Bay of Bengal, in the western Indian Ocean. It is known to dwell at a depth of 234 metres (768 ft).
Rhynchoconger trewavasae is an eel in the family Congridae. It was described by Adam Ben-Tuvia in 1993. It is a marine, deep water-dwelling eel which is known from the western Indian Ocean, including the Gulf of Aqaba and possibly the Gulf of Suez. A single specimen was recorded in the Mediterranean Sea from Israel in 1993. It dwells at a depth range of 300 to 500 metres, and swims in a zigzag motion near the bottom. Males can reach a maximum total length of 57 centimetres (22 in), but more commonly reach a TL of 45 centimetres (18 in).
Cynoponticus coniceps, the red pike conger or conehead eel,) is an eel in the family Muraenesocidae. It was described by David Starr Jordan and Charles Henry Gilbert in 1882, originally under the genus Muraenesox. It is a marine, tropical eel which is known from the eastern central and southeastern Pacific Ocean, including Mexico, Ecuador, Colombia, Costa Rica, Guatemala, El Salvador, Honduras, Panama, Peru, and Nicaragua. It dwells at a depth range of 10 to 100 metres, and inhabits sediments of sand and mud. Males can reach a maximum total length of 202 centimetres (80 in); the maximum recorded weight is 11.0 kilograms (24.3 lb).
