Diagnosis and interrelationships of fishes of the genus Channa Scopoli (Teleostei: Channidae) of northeastern India

Abstract

Diagnostic characters of nine species of the genus Channa Scopoli of northeastern India are given. Examination of morphologicaland osteological characters revealed that the fish under study comprised two phylectic groups: marulius and gachua. The Marulius group ischaracteristic by having a very prominent V-shaped sharp isthmus, cephalic sensory pores arranged in groups, absence of scales on thelower jaw, a sharp prominent spinelike hypurapophysis, more branchial toothplates than epibranchial, and an elongated urostyle. TheGachua group is characterized by a U-shaped isthmus, cephalic sensory pores evenly arranged in a single row, the presence of one or twolarge cycloid scales on each side of the lower jaw, absence of a sharp prominent spine-like hypurapophysis, absence or presence of onetooth plate in the epibranchial, and absence of an elongated urostyle. An elongated bone is present in between two last hemal spines of allspecies examined. A key to known species of Channa of northeastern India is also given.