Influence of periphyton based culture systems on growth performance of fringe-lipped carp Labeo fimbriatus (Bloch, 1795) during fry to fingerling rearing

Abstract

A 90 days experiment was conducted in outdoor circular cement tanks to evaluate the growth and survival of Labeo fimbriatus fry when provided with sugarcane bagasse as a periphyton substrate. In all, there were six treatments viz., feed (T1), substrate (T2), substrate + feed (T3), substrate in tank bottom + feed (T4) and substrate + feed + double stocking density (T5). Sugarcane bagasse was hung vertically at 2 t ha-1, except in T3, where it was applied at the tank bottom. L. fimbriatus fry were stocked @ 30 nos. m-3 in all tanks, except in T5 which received double stocking density of 60 fry m-3. No significant variation was observed between the different treatments with respect to water quality parameters monitored viz., pH, temperature, dissolved oxygen, total alkalinity and secchi disc visibility. On termination of the experiment, in treatment T4, significantly higher (p< 0.05) growth in terms of length and weight, specific growth rate (SGR) and percent weight gain were recorded as compared to the other treatments. Provision of substrate in the water column or at the tank
bottom in addition to feed, significantly (p<0.05) enhanced weight, specific growth rate (SGR) and percent weight gain. Survival was lower when the substrate was provided at the tank bottom. The results indicated that stocking density can be doubled in tanks provided with substrates, without compromising growth and survival of L. fimbriatus fry.