Scobinichthys granulatus
Uncommon but widespread on temperate reefs, this speckled filefish turns up year-round in New South Wales, Victoria and South Australia.
A small, deep-bodied filefish around 21 cm long with a compressed, almost diamond-shaped profile and a rough, granular skin texture rather than true scales. Colour is mottled grey-green to brown with fine dark speckling and blotches that shift to match the surrounding reef, breaking up its outline. Look for the single slender dorsal spine set well back on the head, a small pointed snout, and the slow, hovering swimming style typical of filefish.
Divers usually find it hovering low and unhurried over rocky reef and weedy ground, using its mottled skin to blend into sponges, algae and rubble rather than fleeing. It is not shy exactly, more indifferent, often letting a diver get close before drifting off with slow, deliberate fin strokes. Most sightings are on daytime dives among reef structure rather than in open water.
Like other filefish, it can lock that single dorsal spine upright and wedge itself into a crevice, making it awkward for a predator to pull out once it has tucked into a hole.
Sighting records show no strong seasonal pattern, so it is logged year-round. Its observed range of 15.1 to 23.3C matches the temperate conditions found on southern Australian reefs through most of the year.
Reef neighbours a diver could mistake it for. Use the identification notes above to tell them apart.
Most reliably logged on temperate reefs around Australia, with the strongest presence in New South Wales and good numbers also in Victoria, South Australia and Western Australia. It is not found outside Australian waters in the current diver record, making it a distinctly Australian reef fish to look for.
Mapping where Rough Leatherjacket is logged…
It is an Australian speciality, most commonly logged in New South Wales, with solid numbers in Victoria, South Australia and Western Australia. Outside Australia it does not turn up in diver records.
There is no clear seasonal pattern in the sighting data, so it can be found year-round on the temperate reefs it favours, generally in water between 15 and 23C.
Look for a small, flattened, diamond-shaped fish around 21 cm with rough, sandpaper-like skin and mottled grey-green speckling that camouflages it against reef and rubble. A single slim dorsal spine set back on the head is a good confirming feature.
They reach around 21 cm in length, a small, easily overlooked reef fish rather than anything imposing in the water.
No, they pose no threat to divers and are generally unbothered by a calm, close approach.
Site and sighting data is aggregated from diver logs, iNaturalist and GBIF. For taxonomy and conservation status:
Whitespotted Filefish
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