Evaluation of growth performance and compatibility of Labeo fimbriatus (Bloch, 1795) with major carps in polyculture system

Abstract

Growth performance and compatibility of Labeo fimbriatus were studied in a yearlong experimental trial of grow - out carp polyculture in earthen ponds. At a combined stocking density of 7500 fingerlings ha-1, the three different species combinations evaluated were: T1 (Control): catla, silver carp, rohu and mrigal at 0.5:0.5:1:1; T2: catla, silver carp, rohu and L. fimbriatus at 0.5:0.5:1:1 and T3: catla, silver carp, mrigal and L. fimbriatus at 0.5:0.5:1:1. Incorporation of L. fimbriatus into the carp polyculture system did not affect survival of any other carp irrespective of species combination. However, except silver carp, growth of all other species were affected by the species combination. While silver carp and catla showed similar growth in T1 and T2, harvested size of L. fimbriatus in T2 was 30% less than mrigal in T1. The 11.4% lower growth (p<0.09) of L. fimbriatus in presence of mrigal in T3 compared to its counterpart in T2, in absence of the latter, suggested existence of inter-specific competition between the two species in T3. Such results suggested feasibility of incorporating L. fimbriatus as an alternative species to mrigal in the major carp based polyculture system without affecting the total biomass yield.