Fanbelly leatherjacket
Monacanthus chinensis
Illustration: Bloom by Day
A mottled cream and brown leatherjacket with a concave snout, one spine on the head and a huge fan of skin slung under the belly that it raises when alarmed. It hovers nose-down in weed and around pylons, sculling with its dorsal and anal fins, and goes nowhere in a hurry.
how to recognise it
- cream to yellowish or brownish, blotched and mottled in brown
- a very large skin flap on the belly — the fan it is named for
- a concave snout and a single spine on the head
- brown bands on the tail, with a filament trailing from its upper part
Field marks read from Fishes of Australia, 2026-10-16. Our wording, their facts. Max size 40 cm TL.
facts
- habitat
- estuary
- size
- ~25 cm, to 40 cm
Max size from Fishes of Australia (40 cm TL); the typical size is Bluebird’s, not from a cited source
- records near here
- 91 at 3 of 6 spots
A count of occurrence records near these spots, not abundance. Records are where someone looked.
when it has been recorded
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A gap means no record in the sample, not absence.
the rule
no QLD rule listed — check before you dive
no NSW rule listed — check before you dive
no closed season recorded for this species — that is not the same as open; check the official page
Rules checked 2026-10-13 against qld.gov.au
Rules change. Check before you dive.
Occurrence data: Atlas of Living Australia (ala.org.au), CC-BY 4.0.
Diver transect counts: Reef Life Survey (reeflifesurvey.com), CC-BY 4.0, supplied via ALA.
Target and protected species: Queensland tidal-water size and possession limits (qld.gov.au) and NSW saltwater bag and size limits plus threatened species lists (dpird.nsw.gov.au).
Habitat and size: Bluebird, approximate, from general knowledge. Not cited. FishBase is CC BY-NC and this app is commercial, so it is not used.
Description written for Bloom. RECORDS ARE WHERE SOMEONE LOOKED, NOT WHERE THE FISH ARE. A record count is a count of records near here and nothing else -- it is not abundance, and a species with few records is not rare. Absence of records is not absence of fish.
Diver transect counts: Reef Life Survey (reeflifesurvey.com), CC-BY 4.0, supplied via ALA.
Target and protected species: Queensland tidal-water size and possession limits (qld.gov.au) and NSW saltwater bag and size limits plus threatened species lists (dpird.nsw.gov.au).
Habitat and size: Bluebird, approximate, from general knowledge. Not cited. FishBase is CC BY-NC and this app is commercial, so it is not used.
Description written for Bloom. RECORDS ARE WHERE SOMEONE LOOKED, NOT WHERE THE FISH ARE. A record count is a count of records near here and nothing else -- it is not abundance, and a species with few records is not rare. Absence of records is not absence of fish.