Hagfish · Myxiniformes · Myxinidae

Pacific Hagfish

Eptatretus stoutii

Data Deficient

There is not enough information to assess its risk of extinction. See full glossary

The Pacific hagfish, sometimes wrongly called the "slime eel", is an agnathan fish of the family Myxinidae. It lives at abyssal depths in the Pacific Ocean, although individuals have been found in Morrocoy National Park in Venezuela. It is a living fossil, and to look at one is to look back to the Palaeozoic era, when the jawless fishes were the only vertebrates in existence. When a diving team goes down to look at the abyssal plains, their breathing tubes have repeatedly been blocked by the slime or mucus these animals use to escape when frightened.

Weight

up to 1.4 kg

Size

up to 63.5 cm

Diet

Carnivore

Feeds mainly on other animals.

Activity

Nocturnal

Active mainly at night.

Social structure

Solitary

Lives and hunts alone, joining others only to breed.

Sighting difficulty

Unknown

OceanCarnivore Nocturnal Solitary Fish Ocean

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Fun facts

A single pinch on the tail of a 45 cm adult triggers the production of 0.9 litres of slime, some seven times the animal's own volume. No other material, biological or synthetic, expands so much in so little time.
The slime forms in under half a second: coiled threads unwind and the mucus swells, trapping water and clogging the predator's mouth and gills.
It has no jaws: it grips the flesh with rasping plates on its tongue and ties its own body into a knot to pull and tear it free.
It is a scavenger: it finds a carcass by smell, enters through the mouth or the anus and consumes it from the inside out, leaving nothing but skin and bones.
With its extremely slow metabolism it can go up to seven months without eating.
Despite more than a century of searching, only some 200 fertilised eggs have been found in Monterey Bay: its reproduction remains a mystery.

Life cycle & biology

Habitat & environment: Muddy bottoms of the eastern Pacific, from south-east Alaska to Baja California, between 16 and 966 m and mostly between 40 and 100 m; it shelters buried in the sediment
Sexual maturity: Length at first maturity 42 cm

Sources consulted: https://es.wikipedia.org/wiki/Eptatretus_stoutii