New description of a Bagrid Catfish Mystus dibrugarensis (Chaudhuri, 1913) from Dihing river of Upper Assam

Abstract

Proper description helps in correct identification of a species. The present work was focused on description of Mystus dibrugarensis i.e. a highly localized fish species found in the upper Brahmaputra basin by using morphometric and meristic measurements. It belongs to the Bagridae family, distinctly differs from the other native variety of Mystus in the presence of two black spot; one at the base of the operculum and another spot at the caudal peduncle region. A distinct black mid lateral line connects the two spot. The caudal fin is forked and upper lobe is longer and pointed than the lower lobe. Male possesses a distinct genital papilla whereas the female has a round genital opening in front of the anal fin.