''Eptatretus deani'', the black hagfish, is a species of hagfish. Common to other species of hagfish, their unusual feeding habits and

slime Slime may refer to: Biology * Slime mold, a broad term often referring to roughly six groups of Eukaryotes * Biofilm, an aggregate of microorganisms in which cells adhere to each other and/or to a surface * Slimy (fish), also known as the pony ...

-producing capabilities have led members of the scientific and popular media to dub the hagfish as the most "disgusting" of all sea creatures. Although hagfish are sometimes called "slime eels", they are not

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 ...

s at all.

Description

This eel-like species is uniform black, or dark brown. It can also appear prune-colored, and often piebald with light spots. The edges of the ventral finfolds and caudal may have a light colour. Unlike the Pacific hagfish, the black hagfish does not have a white ring around their gill pores. It has no true fins, but instead, one dorsal finfold, far back on its body. It has a moderately broad and round caudal, with ray-like markings. The ventral finfold is very low. The black hagfish is scaleless, and ranges from 30 - , with an average maximum overall length of . This species has four hearts, and 10 to 14 pairs of gill pores, It has rudimentary eyes. Although they have poor vision, they have a highly developed sense of smell and touch. The head of this species has one, large nostril, and eight barbels that surround the mouth and nostril. They have two parallel rows of horny teeth.

Distribution

Black hagfish are strictly marine, and are found in the

Eastern Pacific The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south, and is bounded by the continen ...

from southeastern

Alaska Alaska ( ; russian: Аляска, Alyaska; ale, Alax̂sxax̂; ; ems, Alas'kaaq; Yup'ik: ''Alaskaq''; tli, Anáaski) is a state located in the Western United States on the northwest extremity of North America. A semi-exclave of the U.S., ...

to central Baja

California California is a U.S. state, state in the Western United States, located along the West Coast of the United States, Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the List of states and territori ...

, and

Mexico Mexico (Spanish: México), officially the United Mexican States, is a country in the southern portion of North America. It is bordered to the north by the United States; to the south and west by the Pacific Ocean; to the southeast by Guatema ...

. These

Bathydemersal Demersal fish, also known as groundfish, live and feed on or near the bottom of seas or lakes (the demersal zone).Walrond Carl . "Coastal fish - Fish of the open sea floor"Te Ara - the Encyclopedia of New Zealand. Updated 2 March 2009 They occ ...

fish live in the mesopelagic to

abyssal The abyssal zone or abyssopelagic zone is a layer of the pelagic zone of the ocean. "Abyss" derives from the Greek word , meaning bottomless. At depths of , this zone remains in perpetual darkness. It covers 83% of the total area of the ocean an ...

Pacific ocean The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south, and is bounded by the continen ...

, near the ocean floor between depths of 103 and 2743 metres.

Behaviour

Like other hagfish, this species attacks hook-caught or trap-caught fish. They burrow into the prey's body to consume the flesh and viscera within. They also feed on carcases of fish that have died and sunk to the ocean floor.

Uses

In many parts of the world, including the US, hagfish skin is used for clothing, belts, or other accessories. In the United States, the black hagfish has been trapped for commercial purposes. Trapping in

Oregon Oregon () is a U.S. state, state in the Pacific Northwest region of the Western United States. The Columbia River delineates much of Oregon's northern boundary with Washington (state), Washington, while the Snake River delineates much of it ...

began in October, 1988 in Newport. The hagfish are frozen whole, at sea, and then shipped to South Korea.Pacific Hagfish, Eptatretus stouti, and Black Hagfish, E. deani: The Oregon Fishery and Port Sampling Observations, 1988-92
/ref> Recent studies have shown that hagfish slime has similar properties of spider silk, strong and light. If hagfish slime could be replicated in laboratories it could replace artificial materials, like nylon, in women's stockings and workout pants. This would ultimately be better for the environment since nylon is produced from petroleum, and hagfish slime threads could be implanted into bacterium and grown with no harm to the environment.

Egg characteristics

Mature females usually contain up to 42 eggs. The average is 4 eggs over 5 mm long. Mature black hagfish females often contain various sized groups of eggs—sometimes having three distinct size groups. Contained in a typical gonad might be: one group with eggs from 19 – 22 mm, another group with eggs ranging from 1 – 4 mm, and a third group of eggs less than 1mm long. Ovaries often contain over 200 eggs, each less than 1 mm.

Gonad stages

The adjacent image shows the various stages of egg development: *1. Eggs in an immature female. All eggs are less than 1 mm long, round, and are present along the length of gonad. *2. Maturing female. Oblong eggs, most less than 5 mm long, with a few longer than 1 mm. *3. Mature ova in developing female. Some eggs are longer than 5 mm. *4. Mature ova in developed female. At both ends of egg, hooks are present. *5. Mature, spent female showing large, empty ovarian capsules (and some oblong eggs). *6. Showing three different size groups of eggs in gonad.

Slime

Black hagfish produce copious amounts of

as a defense mechanism. Deep-sea diving equipment is known to have been fouled by large amounts of hagfish slime near the bottom of the ocean, extruded by the eel-like fish when they are alarmed. The slime comprises mature thread cells, up to long that are coiled and thread-like.Acta zoologica. Internationell tidskrift for zoologi, Volumes 62-63, p.137

References

External links

*
Images of black hagfish devouring a fish
{{Taxonbar, from=Q4499974 Myxinidae Scavengers Western North American coastal fauna Fish described in 1907