PAKISTAN JOURNAL OF ZOOLOGY, vol.49, no.6, pp.2257-2261, 2017 (SCI-Expanded)
The objective of the present study is to analyze the growth performance of rainbow trout (Oncorhynchus mykiss) (G) and brown trout (Salmo trutta ssp) (K) monoculture and polyculture in 75-25%, 66-34% and 50-50% stocking rates and its effects on food utilization and to determine the results with respect to aquaculture. Stocking was conducted in 5 different ratios in the study and each different stocking ratio was considered as a group and 24 fish were used in each group. Study groups were named based on stocking ratio percentages as G, K, G75K25, G66K34 and G50K50 and the study lasted 80 days. When the growth parameters in polycultures of rainbow trout and brown trout are considered, it was determined that the growth rates were not statistically different between rainbow trout monoculture and rainbow trout G75K25 and G50K50 groups, however rainbow trout in G66K34 experienced statistically significantly less growth when compared to others (p<0.05). Growth parameters of brown trout in polycultures demonstrated that the best growth was observed in G66K34 polyculture group (p<0.05). Study results showed that there was no significant difference between the groups based on food conversion coefficients and survival rates (p>0.05). As a result, it was determined that brown trout monoculture was the most advantegous group followed by G50K50 polyculture group, and when ecological and environmental parameters are concerned, G75K25 group, which consumed statistically significantly less food and demonstrated a lower food conversion ratio, would be more beneficial, and for fish breeders, who would like to increase the growth rate of the trout, G66K34 polyculture group would be more useful when compared to brown trout monoculture.