Rough Leatherjackets form part of the filefish family, Monacanthidae. Although all leatherjackets possess small scales covered with minute spines, those of the Rough Leatherjacket are more prominent and sharp, resembling miniature rose thorns across their skin. They can be easily recognised by a large dorsal spine (a common feature of all leatherjackets), small beak-like teeth a dark blotch above the pectoral fin and a small skin flap below the belly. The base colour of the Rough Leatherjacket is variable from brown to green to grey to white and they often exhibit dark blotches and iridescent blue dotting down the body. Their tail has a characteristic stripey pattern, unique to the Rough Leatherjacket.
The Rough Leatherjacket is commonly found in the shallow temperate waters from southern Queensland around southern Australia to west Shark Bay Western Australia. They prefer to inhabit seagrass beds and are abundant on estuarine reefs and feed on a range of invertebrates and algae. The Rough Leatherjacket grows to a maximum length of 35 centimetres.
Occurrence at the Busselton Jetty
The Rough Leatherjacket can be observed from the Underwater Observatory on a daily basis, though numbers of these sightings seem to drop off throughout the summer months. They are often seen in schools feeding on the jetty piles and are also seen swimming amongst the seagrass. A curious fish, Rough Leatherjackets will swim up toward the Observatory windows and raise their dorsal spines.
Image by: O. Rynvis