Living fossil captured

14th January 2015

The frilled shark (Chlamydoselachus anguineus) gains its name from its six pairs of frill like gills. It is one of two remaining species of this ancient family which dates back 80 million years.

It has a wide but patchy distribution in the Atlantic and Pacific Oceans on the outer and upper continental slope, generally near the bottom, though there is evidence of substantial upward movements. It has been caught as deep as 1,570m but is uncommon below 1,200m.

Exhibiting several primitive features, the frilled shark is often termed a “living fossil”. It reaches a length of 2.0m and has a dark brown, eel-like body with the dorsal, pelvic, and anal fins placed far back. Its common name comes from the frilly or fringed appearance of its six pairs of gill slits.

Seldom observed, the frilled shark may capture prey by bending its body and lunging forward like a snake. The long, extremely flexible jaws enable it to swallow prey whole, while its 300 needle-shaped teeth aligned in 25 rows make it difficult for the prey to escape. Some literature suggests its body shape allows it to feed along crevices on cephalopods, bony fishes and other sharks. A large liver packed with low-density oils and hydrocarbons allows it to maintain neutral buoyancy at depth.

This individual was captured by a trawl vessel and was near maximum length. It was offered to CSIRO but they already hold specimens.