1. Commonly called flat-fish. Body divided into head, trunk and tail.
2. Fish is strongly compressed and asymmetrically flattened. Head is asymmetrical, the posterior cranium is normal but the anterior cranium is twisted with two orbits on one side in the adult and hence the fish is sinistral. Eyes are found on the left side. In some cases eyes can be
dextral i.e., lying on the right side. Nostril also on the left side.
3. Body scales are imbricate. Cycloid or ctenoid.
4. Mouth is narrow and protactile. It has sharp chisel-like teeth on the jaws and flattened crushing teeth in the pharynx.
5. Right side is white, the left side is pigmented while the lower side is silvery white.
6. The dorsal and anal fins are elongated, expanded and continue up to the beginning of tail. Dorsal and anal fins supported by fin rays. Pectoral fins placed high up and ventral fin below pectoral fin. Caudal fin fan shaped.
7. Air bladder is physoclistous. Lateral line and operculum present a spiracle absent.
Source:
1. Practical Zoology Vertebrates by S.S.Lal. 2. A Manual of Practical Zoology Chordates by Dr. P.S. Verma.
