Morphology and Reproductive Biology of Blue Perch Badis assamensis Ahl 1937 Recorded From a Hill Stream in Assam, India

Abstract

A badid, Badis assamensis Ahl, 1937, was recorded for the first time from the intermediate zone of a semi-torrential stream called Basistha in Assam, which is a small tributary of the river Brahmaputra. The fish species Badis assamensis is currently listed in the data deficient (DD) category of IUCN. The species has previously been reported in swampy wetlands in the upper reaches of the Brahmaputra valley in Assam; with no detail description on its biology however. The current work redescribes morphology and presents detail reproductive biology of this species based on fresh collection of 377 individuals from the Basistha. length-weight relationships (LWR) analysed in this species indicated an isometric growth; and condition factor (K) indicated a suitable habitat for this species. Badis assamensis exhibits a non-seasonal breeding behaviour twice a year, as analysed from the Gonado-somatic and ovarian indices. During certain period of the year, local people use unscientific ways of fish collection thereby resulting in a steep decline in fish population. The study is believed to lay an insight into this species' geographical range from a swampy wetland habitat in upper reaches of the Brahmaputra basin; to a semi-torrential hill stream habitat in the lower Brahmaputra sub-basin; thereby providing baseline information on this DD species. Analysis of morphometric and reproductive parameters of this species not reported earlier is the major highlight of the present study.