Hagfish, of the class Myxini and order Myxiniformes, are eel-shaped jawless fish. They are the only known living animals that have a skull but no vertebral column, although hagfish do have rudimentary vertebrae. Hagfish are marine predators and scavengers. Hagfish defend themselves against predators by releasing copious amounts of slime from glands in their skin.
Eptatretus springeri, the Gulf hagfish, is a bathydemersal vertebrate which lives primarily in the northeastern Gulf of Mexico. It has been observed feeding at and around brine pools: areas of high salinity which resemble lakes on the ocean floor that do not mix with the surrounding water due to difference in density. The high salt content, approximately 200 ppt compared to 35 ppt for standard seawater, creates a buoyant surface which renders oceanic submersibles unable to descend into the pool. It is believed that the inside of the pools only supports microbial life, while the majority of macroscopic life, such as methane-utilizing mussels, exists on the edges. The Gulf hagfish feeds on the primary producers of these environments, as well as other predators.
The broadgilled hagfish or New Zealand hagfish, also known by its Māori language name tuere, is a hagfish found around New Zealand and the Chatham Islands as well as around the south and east coasts of Australia, at depths between 1 and 900 metres.
Oplegnathus is currently the sole recognized genus in the knifejaw family (Oplegnathidae) of marine perciform fishes. The largest, the Cape knifejaw, can reach a maximum length around 90 cm (35 in). Knifejaws have teeth fused into a parrot-like beak in adulthood. They feed on barnacles and mollusks, and are fished commercially. They are native to the Indian and Pacific Oceans.
The Pacific hagfish is a species of hagfish. It lives in the mesopelagic to abyssal Pacific ocean, near the ocean floor. It is a jawless fish and has a body plan that resembles early paleozoic fish. They are able to excrete prodigious amounts of slime in self-defense.
Eptatretus is a large genus of hagfish.
The inshore hagfish is a hagfish found in the Northwest Pacific, from the Sea of Japan and across eastern Japan to Taiwan. It has six pairs of gill pouches and gill apertures. These hagfish are found in the sublittoral zone. They live usually buried in the bottom mud and migrate into deeper water to spawn. The inshore hagfish is the only member of the Myxinidae family having a seasonal reproductive cycle.
Myxine is a genus of hagfish, from the Greek μυξῖνος. It is the type genus of the class Myxini.
The southern hagfish is a hagfish of the genus Myxine.
Eptatretus bischoffii is a common hagfish of the genus Eptatretus. Its maximum length is 55 centimetres (22 in). It lives in a demersal, non-migratory, marine habitat with its depth range between 8–50 m. It can survive in only temperate zones. These organisms are found in the South Pacific, mainly, Chile. It is harmless to humans.
Myxine glutinosa, known as the Atlantic hagfish in North America, and often simply as the hagfish in Europe, is a species of jawless fish of the genus Myxine.
Eptatretus deani, the black hagfish, is a species of hagfish.
Nemamyxine is a genus of hagfish.
Notomyxine tridentiger is a species of hagfish that occurs in the Atlantic Ocean off the southern coasts of South America. It is the only member of the genus Notomyxine. It can be found in the temperate waters of the Southeast Pacific and Southwest Atlantic, as well as the southern coasts of South America. It can reach a maximum length of 57 cm.
Rubicundus is a genus of hagfishes, the only member of the subfamily Rubicundinae. All species in it were formerly classified in Eptatretus. R. eos, R. lakeside, and R. rubicundus are known from single specimens caught in the Tasman Sea, Galápagos, and Taiwan, respectively. They are named after the distinctive red coloration that all species share.
Apsilus is a small genus of marine ray-finned fish, snappers belonging to the family Lutjanidae. The two species within the genus are native to the Atlantic Ocean,
Eptatretus polytrema, the fourteen-gill hagfish or Chilean hagfish, is a demersal and non-migratory hagfish of the genus Eptatretus. It is found in muddy and rocky bottoms of the southeastern area of the Pacific Ocean near the coast of Chile between Coquimbo and Puerto Montt, at depths between 10 and 350 m. This hagfish can reach a length of 93 cm. It is only known from a few specimens and has not been recorded since 1988.
Chirodactylus brachydactylus, the twotone fingerfin, is a species of marine fish in the fingerfin (morwongs) family of order Perciformes. It is native to the coast of southern Africa.
Pachymetopon aeneum, the blue hottentot, is a species of marine demersal ray-finned fish belonging to the family which includes the seabreams and porgies. It is endemic to the south and east coasts of South Africa.
