Crecimiento y supervivencia de larvas de Rhamdia quelen criadas en estanques luego de diferentes períodos de larvicultura intensiva

Abstract

The aim of this study was to evaluate the effect of the duration of intensive larviculture on growth and survival of Rhamdia quelen larvae under experimental conditions. A total of four experimental treatments were performed, consisting of a semi-intensive larviculture (L0) in ponds at the start of exogenous feeding, or intensive larviculture for 5 (L1), 10 (L2) and 15 (L3) days post-hatching (dph) before transfer to ponds. The experience lasted for 45 days. At the end of the complete cycle (45 dph), L0 and L1 showed the highest weight values (12.8 and 10.4 g, respectively). In turn, L0 presented lower survival rate (0.7%, p<0.05), while L2 showed intermediate survival values, obtaining the highest final biomass (p<0.05). The analysis of the intensive larviculture stage revealed a negative relationship on the survival rate of larvae based on their permanence in the system (73.6, 58.9 and 44% for L1, L2 and L3, respectively), whereas this relationship was positive once the larvae were placed in ponds (5.25, 32.58 and 49.88% for L1, L2 and L3, respectively). The most suitable time for larvae relocation in external ponds under the experimental conditions would be at 10 dph, since acceptable survival rates and appropriate weights are obtained for the beginning of fingerling rearing stage.