Semi-natural Breeding of Chinese Carps

A set of simple facilities for spawning and hatching Chinese carps using the "Chinese natural spawning method" were constructed in a private fish-farm and a Chinese round spawning tank was also built in a State Hatchery in Guilan Province. During the breeding season 544 female and 611 male of grass carp, silver carp and bighead carp were breeded using one or two injections of LRH-A, HCG and PG hormones. The eggs released by using the this semi-natural method were 6% higher in grass carp, 37.72% higher in silver carp and 16.7% higher in bighead carp, compared to the artificial method. The mortality rate of grass carp and silver carp female brooders were 3.34%, 45.19% respectively. This can be attributed to the applied "Chinese method", which prevent the brooders from getting injured. The Chinese method was employed a few hours after the fertilization and the number of the fully swollen eggs in grass carp, silver carp and bighead carp were respectively 25%, 17% and 12% higher. Considerin.....