Pseudorhombus oligodon   (Bleeker,  1854) (Fish)
Organism information awaits expert curation
Class: Actinopterygii

Image copyrights: FAO

Size: Maximum about 25 cm; common 10 to 20 cm

Color: Eyed side brown, with a varying pattern of darker blotches and rings, but always 1 large, dark blotch at anterior end of straight part of lateral line.

Upper profile evenly convex. Height 1.8-2, 2-2.4 in length with caudal. Head 2.9-3.5, 3.4-4.1 in length with caudal. Eyes nearly equal, 4.1-6.1 in head, 2.5-3 in postorbital part of head, separated by a narrow ridge, above each other or the upper one somewhat in front of the lower. Nostrils on colored side in a horizontal line, the hinder one a large hole, the anterior one very small and provided with a flap, at the blind side the anterior nostril is placed somewhat higher and bears a tentacle in stead of a flap. Maxillary scaly on colored side, reaching to below hind border of eye, at least in full grown specimens, 2-2.2 in head. Mouth strongly oblique. Teeth in both jaws caninoid and wide apart anteriorly, small and crowded posteriorly. The canines are often hastate, 3 to 5 in each side of upper jaw and 7-10 in each side of lower jaw. Tongue smooth. Origin of dorsal beginning on blind side, above posterior nostril, a line through both reaches the maxillary in its anterior half. All dorsal and anal rays simple. The anterior rays the shortest, the sub-posterior ones the longest. Origin of anal before vertical through hind border of operculum. No praeanal spine. Dorsal and anal ending close to caudal, which is bluntly pointed. Scales ctenoid on both sides, covering the head with exception of the snout. The forward prolongation of the lateral line reaches the upper profile at the 8th or 9th dorsal ray. Pectoral of colored side longer, that of blind side shorter than postorbital part of head. Ventrals equal, somewhat shorter than snout and eye. Nine to eleven compressed lanceolate gillrakers on lower branch of first arch, dentated behind and not quite as long as half diameter of eye.

Remarks: Values in above description denote proportions.

Synonym (s)
Rhombus oligodon Bleeker, 1854
Pseudorhombus malayanus Bleeker, 1866
Pseudorhombus oligodon Jordan and Evermann, 1902
Pseudorhombus cinnamomeus Jordan and Starks, 1906
Pseudorhombus malayanus Jordan and Richardson, 1908
Pseudorhombus oligodon Snyder, 1912

Common Name (s)
• Roughscale Flounder (English)
Economic Importance and Threats
Importance:  Commercial
(Marketed mostly fresh)

Habitat:  Benthic, Sandy, Muddy
Trophic Level:  Consumer
Prey:  Benthic animals


• Bay of Bengal INDIA

Literature Source(s)
  • Society for the Management of European Biodiversity Data (2009) World Register of Marine Species (WoRMS) Available at -
  • Weber, M; Beaufort, LF (1929) The fishes of the Indo-Australian Archipelago E. J. Brill Ltd. 5 458 pp Available at - NIO, Goa
  • Fischer, W and Whitehead, PJP (1974) FAO species identification sheets for fishery purposes. Eastern Indian Ocean - Fishing Area 57 and Western Central Pacific - Fishing Area 71 FAO, Rome 1 Available at -

Page last updated on:2010-05-10

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