Evaluation of growth performance of Labeo fimbriatus (Bloch), Labeo gonius (Hamilton) and Puntius gonionotus (Bleeker) in polyculture with Labeo rohita (Hamilton) during fingerlings rearing at varied densities

Fingerling rearing of two minor carps fringe-lipped carp (Labeo fimbriatus), kuria labeo (Labeo gonius) and silver barb (Puntius gonionotus) along with the Indian major carp rohu (Labeo rohita) was carried out in outdoor concrete seed rearing system for 90 days at four densities viz., 10, 20, 30 and 40 m− 2 to evaluate their relative growth performance and feasibility of polyculture during seed rearing. All the species except rohu showed more than 90% survival at all the densities and did not vary with regard to densities, whereas, rohu showed significantly lower survival of 64.5–66.8% in the two higher densities. Silver barb and kuria labeo showed higher growth potential than rohu and fringe-lipped carp while growth in the latter two was similar at all the densities. The study also revealed better fingerling production attributes, both in terms of number and biomass yield, at combined density of 40 m− 2 compared to 10–30 m− 2 and suggested the former to be ideal density for fingerling rearing of these species under polyculture in concrete tanks.