Breeding Behaviour and Embryonic Development of Koi Carp (Cyprinus carpio)

Induced breeding experiments of Nikishigoi (koi carp), Cyprinus carpio were conducted in mature males and females by administrating a single intramuscular injection of ovaprim at a dosage of 0.3mL/kg weight. Spawning was observed six hrs after the injection at ambient temperature (26-28℃). The fertilized eggs were adhesive and transparent with diameter ranging between 0.9mm and 1.10mm. Incubation period was 73.00hrs. The hatchlings were transparent and measured 2.7-2.9mm, with a large oval head, a well defined yolk sac and short tail. The yolk got fully absorbed within 3 days and by this time mouth formation was complete and the larvae started exogenous feeding. After 20 days the length of fry ranged between 10mm and 12mm and after 35 days length of the fingerlings ranged from 30-35mm and appeared just like an adult in all respects except sexual maturity.