水産養殖研究開発ジャーナル

概要

Controlled Breeding of Asian Catfish Clarias batrachus using Pituitary Gland Extracts and Ovaprim at different Temperatures, Latency Periods and their Early Development

Kishore Dhara ,Nimai Chandra Saha *

Present study was conducted on induced breeding of commercially important Clarias batrachus due to the non-availability of its quality seeds from the natural resources for environmental degradation, shrinkage of natural breeding ground and illegal killing of juveniles and brood fishes. The aim of the study was to achieve success in fertilization and hatching using various doses of different inducing agents at different temperatures and latency periods followed by stripping method. In this study the developmental stages of fish (fertilized egg to 45th day old fish) were characterized chronologically. A trial was also made to optimize the survival rate of young developing fish upto 45th day by manipulating their feeding schedule and environmental conditions. The breeding experiments were done with pituitary gland extracts (40 and 120 mg/kg. body weight for female and 25 and 50 mg/kg. body weight for male) and Ovaprim (0.8 and 2.0 ml/kg body weight for female and 0.4 and 1.0 ml/kg body weight for male) at 26º, 28º and 30ºC. The highest rates of fertilization (80%) and hatching (71%) of eggs were recorded in Clarias batrachus injected with carp pituitary gland extracts @ 50 mg/kg body weight of male and 120 mg/kg body weight of female at 28ºC with a latency period of 15 hours. The fertilization and hatching rates were 77% and 65% respectively at 28°C at the higher doses of Ovaprim. The highest survival rate (82.5%) of developing fish was achieved supplying zooplankton as live feed upto 12th day followed by alternate supply of zooplankton, boiled egg with vitamin C and chopped tubifex from 13th to 45th day of rearing in indoor polyvinyl chloride tray with minimum fluctuation in temperature and dissolved oxygen.