Effect of salt (NaCl) and estocking density on Betta splendens larviculture

Abstract

This study evaluated the growth and survival of Betta splendens larvae exposed to different salt concentrations (NaCl 0, 2, 4, 6 and 8 g L^-1) and stocking densities (1, 5, 10 and 15 larvae L^-1) during 20 days. A completely randomized design in a 5x4 factorial scheme with three replications was used, and the fish reared in static system. At the end of the experiment were evaluated the final weight, total length, group uniformity, specific growth rate and survival. Total larvae mortality was observed in treatments with 4, 6 and 8 g L^-1, demonstrating the susceptibility of this specie for these concentrations. However, the salinized water with 2 g L^-1 promotes longer larvae when fish were maintained in densities of 10 and 15 larvae L^-1. Further, there were no interactions between the addition of salt and stocking density for the other parameters. However, beneficial effects of salinized water (2 g L^-1) were observed as better growth performance and survival of larvae. Regarding the stocking density, apart from addition of salt, the larvae present best development at density of 5 larvae L^-1. Therefore, the use of salinized water (2 g L^-1) and stocking density of 5 larvae L^-1 is recommended for the Betta splendens larviculture.