Most toothbrush leatherjackets that we see are too young to have the bristles which give the species its common name. The adult fish in this photo from Shelly Beach, Manly has a well-developed set of bristles along the rear half of the body.
The characteristic toothbrush bristles of this species are only developed in adult males - so this shot is of a young fish either male or female... to be determined! Shelly Beach
"Toothbrush leatherjackets are widespread in southern Australia but hard to see as they blend well with their kelp habitat. This brightly coloured male is an exception; juveniles and females are kelp-coloured with variable white spots. Only the male has the toothbrush ""bristles"" you can see here on the rear side of the body. Shark Point, Clovelly"
"I've often been asked why the toothbrush leatherjacket is named as it is. Most of the time it's hard to see why - unless you find a mature male. Then you can see the ""bristles"" along the caudal peduncle, like in this shot. Fairy Bower"