Effect of different salinity level on spawning, fertilization, hatching and survival of common carp, Cyprinus carpio (Linnaeus, ۱۷۵۸) in semi-artificial environment

The effects of various salinity levels among (۰‰, ۵‰, ۱۰‰, ۱۵‰, and ۲۰‰) for successful breeding of common carp, Cyprinus carpio were investigated. The duration of study was ۷۵ days. Ripe broodstock (۳۰) having a mean weight (male ۱۰۲۷±۲.۴g and female ۱۰۸۴.۸±۲۳g) were selected and stocked into spawning tanks (۲۰۰۰ L). The ratio among male and female was ۲:۱. They were fed with commercial floating pelleted feed having ۳۵% crude protein with ۲% body weight twice a day. Broodstock were injected with ovaprim hormone ۰.۵ mg kg-۱ female and male ۰.۲ mg kg-۱ respectively, after successful spawning broodstock were removed from spawning tanks. The results showed that the highest fecundity, fertility, hatchability and survival of fry were obtained on salinity of ۰‰ to ۱۰‰ and significantly decreased on ۱۵‰ and ۲۰‰. The eggs per gram body weight were also recorded in all treatments and highest eggs were obtained, i.e. ۴۵-۶۰ per female on salinity of ۰‰-۱۰‰.  Water temperature (۲۲.۴±۰.۲°C), dissolved oxygen (۶.۵±۰.۲ mg L-۱), pH (۷.۲±۰.۲) and ammonia (less than ۰.۰۳±۰.۰۶ mg L-۱) were monitored throughout the study period. Water quality parameters remained within the recommended range. Our results suggest that common carp, C. carpio may give maximum eggs up to ۱۰ ‰ salinity with ۸۱% survival of the fry.

Keywords:

Common carp , Breeding , Ovaprim , Salinity , Semi-natural