MORPHOMETRIC CHARACTERS AND MERISTIC COUNTS OF CAT FISH, Mystus gulio (HAMILTON, 1822) FROM MARUTHUR ANICUT, TIRUNELVELI DISTRICT

Catfishes comprise an extremely large group of fishes of the order Siluriformes and the vast majority of them inhabit freshwaters. Morphometrics and meristic count are inevitable in fish taxonomy and systematics that help to identify particular taxa up to sub-species level. In the present study, morphometric measurement and meristic count of Mystus gulio from Maruthur wetland were investigated with 22 specimens. Twenty-eight different morphometric characters in percentage of total fish length and head length and five different meristic counts (branched and unbranched rays) were recorded and used to draw the fin formula. The obtained results revealed that the morphometric characters vary depending on the growth and size of the fish; the meristic counts were comparatively similar in all collected specimens, because of species-specific desirable traits. Except for three morphometric characters remaining characters analysed in the study show a positive correlation in percentage of total length and head length. This study endorses the importance of morphometric characters and meristic counts in ascertaining species identification that precedes modern genetic techniques.