EFFECT OF MONTHLY VARIATION IN WATER TEMPERATURE ON ARTIFICIAL BREEDING OF COMMON CARP (CYPRINUS CARPIO L.) A RESEARCH PROJECT TOPIC ON BIOLOGY
The effect of monthly variation in water temperature on artificial breeding of common carp, Cyprinus carpio using ovaprim as an ovulation stimulator was studied. Two years old common carp brood stocks weighing 800-2500grams were obtained from Panyam fish farm in Jos, Nigeria. They were transported to the Department of Biological Sciences, Ahmadu Bello University, Zaria, Nigeria and maintained on commercial feed at 3% body weight for a period of two months before the breeding exercise. A total eighteen (18) brood stock were divided into three (3) temperature groups of 23±1, 26±1 and 29±1°C. Each group had three (3) female and three (3) male brooders. Effect of female body weight on fecundity of common carp was also evaluated. Ovaprim hormone at dosage of 0.5ml/kg and 0.2ml/kg was administered intramuscularly to female and male brooders respectively and simultaneously. Temperature has significant effect (p≤0.05) on latency period of C. carpio; latency period decreased with increase in temperature. At 23±1°C, latency was found to be 16.55±0.13 hours, at 26±1 and 29±1°C latency was 13.00±0.13 and 11.32±0.07 hours respectively. While temperature had no significant effect on the weight of eggs, fecundity and viability of the eggs of C. carpio, increase in female body weight yielded a significant increase (r= 0.97) in the weight of eggs and fecundity of C. carpio. The present results showed that temperature has a significant effect (p≤0.05) on fertilization and hatchability. C. carpio performed best at 26±1°C in terms of fertilization (89.00±3.00%) and hatchability (67.50±2.50%) followed by the temperature of 23±1°C with fertilization of 72.67±1.76% and hatchability of 46.83±0.84%, while the temperature of 29±1°C gave fertilization of 52.30±10.49% and hatchability of 28.98±0.96%. There was also a high significant difference (p≤0.05) in hatching duration of C. carpio eggs incubated at different water temperatures, increase in temperature leads to decrease in the hatching duration of C. carpio eggs.