A striking and easily recognised leatherjacket with a distinct horseshoe-shaped marking on the midside. Males are much more brightly-coloured than females, and adults also have two pairs of curved spines on each side of the caudal peduncle.

Horseshoe leatherjackets are often seen amongst kelp and other macroalgae in deeper bays and estuaries on southern reefs. Juveniles often seek shelter around jetties and piers, while adults may form large schools on offshore reefs.

This Leatherjacket can also present as a much bluer fish.

Like many leatherjackets, this one can be territorial and reward the persistent diver with a sharp nip.