Fanbelly Leatherjacket
Monacanthus chinensis
Fanbelly Leatherjacket (Monacanthus chinensis) is a small, laterally compressed filefish of tropical Indo-Pacific waters, often found around reefs, rubble, and seagrass. It is not a major gamefish, but it can be caught incidentally with light tackle and small baits.

Identification points
- Deep, strongly compressed oval body with a small mouth and pointed snout
- Skin covered in rough, sandpapery bony plates rather than scales
- Tall first dorsal spine over the head and a pale fan-like belly/ventral profile typical of the species
Habitat
Shallow coastal tropical and subtropical habitats, especially coral and rocky reefs, reef flats, lagoon edges, seagrass beds, and rubble areas; usually near structure in sheltered water.
Bait notes
Small pieces of prawn, shrimp, squid, or cut bait on light rigs; tiny soft plastics or small, natural-looking lures can work when fished slowly near structure. It is usually an incidental catch rather than a targeted species.
Behavior
Generally slow-moving and structure-oriented, feeding on small benthic invertebrates and algae picked from the bottom or hard surfaces. It can be wary and may nip baits from cover rather than chase actively.
Caution
Handle carefully because leatherjackets have a sharp dorsal spine and rough skin; avoid touching the spine area. Not a commonly targeted table fish, and local consumption advisories should be checked before eating any reef-associated catch.
Fishing notes
Use ultra-light tackle and small hooks; present baits close to reef, weed, or rubble and keep the retrieve or drift slow. A quiet approach helps, as the fish can be cautious around shallow cover.