A meter (3 ft) of fish pressed flat against the sand with its eyes on top of its head, lying in the open, relying entirely on not being recognized as a fish. Most divers swim over one every dive and see none.
The eyes carry a detail worth looking for: a fringed flap of tissue hangs over each pupil, breaking up the round black shape that would otherwise give the animal away, and it can be raised or lowered. An ambush predator's last problem is always its own eye, and this is one of the neater solutions to it.
It eats by waiting. Small fish and shrimps pass, the mouth opens, and the strike is over before anything registers - no chase, no pursuit, nothing that costs energy.
It also changes sex, but the other way round from most reef fish here: flatheads start male and become female as they grow, so the large individuals are the ones producing eggs. It is a commercial food fish across its range, and the fishery takes the big ones first - which in this arrangement means the females.
head flattened top to bottom, body tapering to a narrow tail
eyes on top of the head with a fringed flap over each pupil
sandy brown with faint bars, and dark bands across the tail
lies in the open on sand, motionless, and lets divers pass
length up to 100 cm
Why it's threatened
Biological resource use
Intentional use: (large scale) [harvest]
Platycephalus indicus is fished commercially throughout its range by bottom trawlers. It is trawled to depths of 30 m, but more often taken at depths less than 15 m (L. Knapp pers. comm. 2007). It is used as a food source and in Traditional Chinese Medicine. This species may be undergoing varying degrees of habitat degradation. As juveniles utilise estuarine and freshwater habitats, they maybe impacted by coastal run-off, and domestic and industrial pollution sources. At present, neither of these are thought to pose a major threat to the population of this species as they do not occur across the entire distribution range.
Threat classification from the IUCN Red List.
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