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What is a wolf eel? © Alamy

What is a wolf eel?

Published: 20th July, 2022 at 18:00
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This voracious eater is not actually an eel...

Wolf eels are scary-looking fish, with crab-crunching teeth, powerful jaws and speckled, grey bodies that look like they’ve been sculpted from a block of granite. They can live for at least 20 years and are enormous, up to 2.4 metres long, although mostly they hide their tapering bodies in caves and crevices in rocky reefs with just their heads sticking out.


Wolf eels are not actually eels, but are members of a fish family known as wolf fish or sea wolves. They live in the cold waters of the North Pacific, from California to the Sea of Japan, down to around 200 metres underwater.

They begin life as small, transparent larvae drifting through the seas, then develop into bright orange juveniles. These young fish swim through open waters until they’re ready to settle down. Then they search for a suitable cave and a partner.

A male and female tend their clutches of eggs, up to 10,000 at a time, protectively wrapping their bodies around them and aerating them with oxygen-rich water. The eggs take four months to hatch and all the while the male and female take turns to leave the cave and hunt. Once the baby eels have hatched and left, the parents set about raising their next clutch. Wolf eels mate for life.

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Dr Helen Scales is a marine biologist, broadcaster and science writer. She is the author of Spirals in Time and The Brilliant Abyss.


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