Effects of varied levels of incorporation of Labeo gonius in carp polyculture system in India

Growth performance of kuria labeo, Labeo gonius as a component species in the major carp polyculture system was evaluated at two incorporation levels against a control without the species through a year‐round grow‐out study in nine earthen ponds (0.08 ha). Three species ratio of catla, silver carp, rohu, mrigal and kuria labeo at 15:15:40:30:0 (T‐1: control), 15:15:40:20:10 (T‐2) and 15:15:40:10:20 (T‐3) were evaluated as three treatments. The carps were stocked at a combined density of 7500 fingerlings ha⁻¹. Silver carp demonstrated the highest survival (75–81%) followed by rohu (70–76%), catla (69–76%), kuria labeo (69–71%) and mrigal (67–69%). Species‐wise yield attributes such as survival, harvest weight, SGR and biomass yield of silver carp, catla and rohu were similar in their respective treatments. Kuria labeo at 10% inclusion demonstrated 12% higher harvest weight than its 20% inclusion. However, such higher weight gain could not affect the total biomass yields of carps which remained similar among the treatments. Furthermore, harvest weight of kuria labeo at 10% inclusion was comparable to that of mrigal when the latter incorporated at 20–30% level. Therefore, the study suggested 10% to be a suitable incorporation level for kuria labeo in the commercial grow‐out carp polyculture system.