The fishery and biology of Mahanadi mahseer Tor mosal mahanadicus (David)

Abstract

Systematic observations have been made from December 1976 to December 1992, on various aspects of biology and fishery of the Mahanadi mahseer Tor mosal mahanadicus (David). The present studies communciate on the status of the fish in the reservoir and in the river stretch below the Dam. Detailed investigations have been made on its habitats, breeding and feeding habits. The studies revealed that Mahanadi mahseer is omnivorous but changes its habits depending upon the availability of food in the habitat. It utilises both the niches like vegetative encrustations on submerged rocks as well as soft tender growth of weeds like VallisnerialChara in the ecosystems. It was observed that males above 260mm and females above 240mm attain maturity. The fecundity of the fish is 10,300 per kg body weight. Two sizes of mature and immature ova were seen in the ovaries in the early part of monsoon. One group of the mature ova is released during mid-August to September whereas the other in between the early part of November and January