Rare Occurrence of a Partially Ambicoloured Flatfish, Brachirusorientalis (Bloch & Schneider, 1801), from Kerala, South West Coast of India

Ambicolouration is an abnormality which occurs as pigmentation in certain areas of the fish. The present study documents the occurrence of partial ambicolouration in Oriental sole, Brachirus orientalis (Bloch and Schneider 1801) collected from central Kerala. The ambicolouration was observed around 38% in the blind side of the fish similar to the colouration in the ocular side restricted to the caudal area which is extended anteriorly to the dorsal and anal fins. Meristic characters did not reveal any significant variation with the normal fish. No visible abnormalities in vertebrae were noticed in the ambicoloured fish.