Wolf Eel (Anarrhichthys ocellatus)

A wolf eel swimming past the Jason undervator at the Oregon Shelf (80 m) site in 2019. Credit: UW/NSF-OOI/WHOI, Dive J2-1162, V19

Curious wolf eels occasionally visit the OOI infrastructure at the Oregon Shelf (80 m) site, swimming on and around the instrumentation while the ROV is working. These menacing-looking (but rarely aggressive) fish are not true eels, because they have pectoral fins and some other anatomical differences. They can grow very large, up to 2.4 m (7 ft 10 in) in length, and adults tend to be mottled gray, brown, or dark green. They use their powerful jaws and mix of canine teeth and posterior molars to crush hard-shelled crustaceans and bivalves, some fish, and other prey items.

Wolf eels can live up to 20 years, and they are monogamous and mate for life, which may explain why they frequently show up in pairs.