Introduction: Common carp (Cyprinus carpio) is one of the most important warm waters cultured fish species in the world. In Development of a sustainable aquaculture system requires year-round fry and fingerlings production of fish. Common carp in tropical and subtropical areas reach maturity at a young age and low weight. In this study, out-of-season common carp fingerligs were used compared to the conventional culture method.

Materials & Methods: 4 ponds of 2 hectares were selected for cultivation. Common carp fingerlings from spring and off-season (autumn) reproductions were used for stocking in the rearing system with conventional density. The beginning of culture period in off-season and spring propagation was done in April and June, respectively. In this study, common carp fingerlings were cultured together with silver carp, big head carp, and rohu species. 6850 fingerling fish were stocked in two hectares. The composition of common carp, silver carp, big head carp, and rohu in off-season carp was 32, 23, 5, and 40%, respectively, with the initial weight of common carp in off-season breeding and spring breedingwas 20 and 6 grams, respectively. Sinking pellet food for common carp with a protein percentage of 26% was used to feed with twice a day. Water parameters were measured during the rearing period. Nutrition and growth parameters including specific growth ratio (SGR), food conversion ratio (FCR), weight gain percentage (WG), survival percentage (SVR), daily growth rate (FI), protein efficiency ratio (PER) were investigated, as well as economic indicators including economic conversion factor and profit index (P) calculated.
Result: The results showed that the growth and nutrition indicators did not show significant differences during the culture period. The food conversion rate in off-season carp was lower than the normal culture of spring breeding carp. Economic coefficient and profit index in off-season breeding compared to Spring carp showed a significant difference (P<0.05). The rearing period in common carp outside the season was shorter and they reached the desired weight in September, while in spring breeding carp, the breeding period was longer and they reached market weight at the end of autumn.

Conclusion: The obtained results showed that the use of common carp in the off-season can contribute to increasing production and shortening the culture period.