مقايسه شاخص هاي تكثير ماهي زينتي سيچلايد گورخري (Cichlasoma nigrofasciatum) د ر نسبتهاي جنسي و د وره هاي نوري متفاوت

Comparing the breeding indices in different sex ratio and photoperiod in Cichlosoma nigrofasciatum as an ornamental fish

This research has focused in breeding of the convict cichlid (Cichlosoma nigrofasciatum). The effects of 5 treatments for sex ratio and 3 treatments for photoperiod on fecundity and fry survival have been surveyed. The sex ratio treatments included: F1:M1, F2:M1, F3:M1, F1:M2, F1:M3 and photoperiod treatments included 3 different lightening periods such as: L10:D14, L12:D12, L14:D10. All of treatments were done 3 times. The result of reproduction including fecundity, hatching and survival percentage of fry within 40 days in different treatments was as following: With increasing the females in an aquarium, the number of eggs in aquarium that contains F1:M1 and F3:M1 decreased from 566 to 344. The treatments in which number of females was more than males, spawning time increased from 10 days (F1:M1) to 26 days (F3:M1). Fry survival percentage declined in treatment of F1:M1 and F3:M1, 99% - 73% i respectively. In photoperiod test, rising the lightening time from 10 hours to 14 hours increased the number of eggs and hatched eggs. But it caused decreasing in spawning time and fry survival percentage. As a result the best sex ratio and photoperiod are offered F1:M1 and L12:D12 respectively.