Monacanthus chinensis (Osbeck, 1765)

Maximum Length

Monacanthus chinensis, commonly known as the fan-bellied leatherjacket, reaches a maximum total length of around 40 centimetres (16 in).

Distinctive Body Features

This fish has a laterally compressed body, and is identifiable by three key features: an upturned pointed snout, a filamentary extension on its fan-shaped caudal fin, and a large dewlap on its underside.

Front Dorsal Fin Structure

The front dorsal fin is made up of one long erectile spine, with a shorter spine positioned behind it.

Soft Ray Counts

The rearmost dorsal fin has between 28 and 34 soft rays, while the anal fin has between 27 and 34 soft rays.

Environment-Dependent Coloration

The species' body color varies based on the environment it inhabits: individuals are dark when swimming over mussel beds, and cream or tan when swimming over sandy seabeds.

Body Markings

Both color variations have irregular darker blotches and streaks across the body.

Native Range

This fish is native to the Indo-Pacific region.

Distribution Extent

Its distribution range stretches from Malaysia and southern Japan, through Indonesia and Samoa, to the western, northern and eastern coasts of Australia.

Species Type

The fan-bellied leatherjacket is a demersal species.

Habitat and Depth Range

It can be found in estuaries, on algae-covered rocky coasts, over muddy and silty seabeds, in seagrass meadows, and on reefs, occurring both inshore and offshore down to depths of around 50 m (164 ft).