Marine life  /  Flatfish  /  Peacock flounder
Reviewed 2026-09-05
Species entry

Peacock flounder

Bothus mancus

Changes its pattern to match the bottom in seconds, and the male's pectoral fin stands straight up.

Size
To 42 cm
Depth
1–80 m
Habitat
Sand and rubble
Active
Daylight
Range
Indo-Pacific
Rarity
Lembeh Strait
2 stars of 5, usually seen in a week
SP-01
peacock flounder · full body · habitat
4:3 · min 2400px

A left-eyed flounder to about 42 cm, the upper side pale grey to sandy brown scattered with pale blue rings and rosettes and a variable number of dark blotches, the underside white. Both eyes lie on the left side of the head and are mounted on short stalks that move independently. Males have a greatly elongated pectoral fin on the eyed side which is raised vertically like a flag in display and territorial disputes. Two English names circulate — peacock flounder and flowery flounder — and the first is also used for the unrelated Atlantic Bothus lunatus. The look-alike to be aware of on black sand is Bothus pantherinus, which is commoner on silt, lacks the blue rings and carries a single large dark blotch on the lateral line; a good proportion of photographs captioned peacock flounder in Indonesia are that species.

Lies on the bottom with a thin covering of sand over the body, changing its pattern to match the substrate within a few seconds of settling on a new one. Feeds on small fish and crustaceans taken with a short lunge. Recorded from the shallows to about 80 m, most often on clean sand and rubble adjacent to reef rather than on the finest silt. Approach is straightforward until the fish decides otherwise, at which point it swims a few metres, settles, and vanishes again.

Where to find:

LocationRarity Best monthsDepthHabitat
Lembeh Strait Indonesia editorial estimate
2 stars of 5, usually seen in a week
Year-round
1–80 m
Sand and rubble

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.

Related species

SP
banded sole
16:10
Banded sole
Soleichthys heterorhinos
SP
caribbean peacock flounder
16:10
Caribbean peacock flounder
Bothus lunatus
SP
cockatoo flounder
16:10
Cockatoo flounder
Samaris cristatus
SP
dwarf flounder
16:10
Dwarf flounder
Engyprosopon