Study on oogenesis and ovarian maturation in puntius pookodensis anna mercy and eapen jacob

Abstract

Puntius pookodensis is a newly identified species of Puntius from Pookode Lake, Wayanad, Kerala, which is an indigenous ornamental fish endemic to the Western Ghats of India. A total number of 112 specimens (77 females and 35 males of size ranging from 20mm to 60mm TL) collected during the period of 2007 were used for the present study of different aspects of breeding biology. They were collected from the Pookode Lake at Wayanad and the distinguishing characters based on external morphology and colour were studied. The gonads were quantified into 6 maturity stages based on external morphology. (Immature virgin, maturing virgin, early ripening, late ripening, ripe and partially spent.). Studies on oocyte distribution of the 6 stages of maturity were done to understand the ova maturation in the ovary. Ovaries show asynchronous development.

The oocyte development was classified into 9 oogenic stages. The first mature male fishes appeared in the 25-30 mm (TL) group and the first mature females appeared in the group of 30-35 mm. All male fishes were mature on reaching a total length of 40 mm and all female fishes on reaching a length of 45 mm total length. The size at first maturity for males was 32.5 mm TL (30-35 mm) and 38.5 mm TL for females (35-40 mm). From the ova diameter frequency distribution of a ripe ovary Puntius pookodensis was found to be a multiple spawner with a protracted spawning with the individual spawning intermittently. Absolute fecundity of the fish ranged from 426 to 823 in fishes of size range 35 to 57mm TL and 0.555 to 2.267 gm body weight. The number and size of eggs were found to be directly proportional to t size and age of the fish. Fecundity showed a positive linear relationship with the length of fish, weight of fish and ovary weight. A complete knowledge on reproductive biology will definitely help in the commercial production and selective breeding under captive condition for the domestic and export market of the indigenous ornamental fish and also conserve the germplasm.