A left-eyed flounder of open sand with a dark blotch where the lateral line curves.
A left-eyed flounder to about 30 cm, both eyes on the upper side and the underside blank white. The upper surface is sandy grey-brown with a dense scatter of dark spots and pale blue rings and blotches, and the character usually relied on is a single strong dark blotch sitting on the lateral line where it curves over the pectoral region. Males have the eyes set further apart and the pectoral fin of the eyed side drawn out into a long filament, which is raised in display. The peacock flounder Bothus mancus shares the range and the pale rings but is more boldly marked with large well-spaced blue rings, has a far longer pectoral filament in the male, lacks the single dominant lateral-line blotch and tends to keep to clean sand beside reef; the small Engyprosopon and Pseudorhombus flounders of the same sand are plainer and rarely exceed 15 cm.
Lies flat on sand and silt and buries by shivering the fin margins until sediment covers everything but the eyes, which move independently and stand clear on short stalks. It changes colour and pattern to match the ground below it within a minute or so. An ambush predator on small fish and crustaceans, taken with a short lunge. Recorded from about 2 to 40 m and one of the animals seen on effectively every muck dive at these destinations, usually as a shape that resolves out of the sand once it moves. A disturbed fish glides a few metres, settles and buries again in the same way, and the second approach is usually closer than the first because the animal has already committed to a spot.
Ratings are per location: 1 means found on most dives that look for it, 5 means a handful of records. Where enough dives have been logged the figure is calculated from them; otherwise it is an editorial estimate, and says so. We publish habitat and destination, not the dive site.