Survival and growth of larval pacamã <em>Lophiosilurus alexandri</em> Steindachner 1876 (Siluriformes, Pimelodidae), in three laboratory stocking densities

Abstract

The aim of this study was to evaluate the effect of three stocking densities on survival and growth of larval pacamã. The experiment was carried out in 12 flow-through systems of 0.43m², with three distinct densities and four replicates each: 150 larvae/system (treatment 01), 250 larvae/system (treatment 02), and 500 larvae/system (treatment 03).The larvae were fed with zooplankton, enumerated and measured for length. With regard to survival pecentage, the treatments gave the following results: 01 - 60%, 02 - 49% and 03 - 37%. Wilcoxon’s Rank Sum Test showed a statistical difference between treatments 01 and 03 (P < 0.05). No such difference was found with regard to larval length, or physical and chemical features of water between the treatments. The results indicate a negative relationship between stocking density and larvae survival rate