Effects of Mono and Polyculture on the Growth of Four Species Fishes in Recirculating Rearing System

In this study, the experiment was conducted for 100 days and all fish were reared in 36 ponds, divided into 3 groups: control group (four fish species monoculture); two species polyculture (S .asotus and C. carassius, S. asotus and C. carpio); three species polyculture (S. asotus, C. carassius and O. niloticus; S. asotus, C. carpio and O. niloticus). We have set three groups. Group A were control group, which was the monoculture of four species. Group B were two species polyculture, and group C were three species polyculture. All water quality parameters evaluated were within acceptable limits for fish culture. Considering the growth parameters, the combination of S. asotus, C. carpio and O. niloticus has the highest growth rate at a ratio of 25:50:25. S. asotus growth is obviously over the other species in all treatments. The growth of C. carassius has been inhibited a lot in polyculture. It"s not a suitable species for polyculture in this experiment. The introduction of O. niloticus in three species polyculture had improved C. carpio growth a lot. There seemed to be a synergistic relationship between C. carpio and O. niloticus.