Stocking density in Colossoma macropomum larviculture, a freshwater fish, in recirculating aquaculture system

摘要

This study aimed to investigate stocking density during larviculture of Colossoma macropomum in recirculating aquaculture system with slightly saline water. Densities of 10 (D-10), 30 (D-30) and 50 (D-50) larvae/L were tested with five replicates each. Larvae were fed with Artemia nauplii during the first 15 days and with commercial diet from day 16 to day 30. Water was maintained at a salinity of 2.01 +/- 0.41 g of salt/L, and performance and survival were evaluated throughout the experiment. At the end of the experiment, larvae of each tank were classified according to size as small-S (<18.0 mm and <0.08 g), medium-M (>18.0 mm and <22.2 mm, >0.08 g and <0.15 g) and large-L (>22.2 mm and >0.15 g), and the size distribution was calculated for each stocking densities evaluated. Larval weight, length and specific growth rate were not affected by the tested stocking densities throughout the experiment (p > .05). Heterogeneity was recorded at 30 days of larviculture for all tested densities with a predominance of class M animals. Survival during feeding with Artemia was not affected by the tested densities (p > .05). Survival during feeding with commercial diet was highest for D-10 and lowest for D-30 (p < .05). Global survival, considering the experiment as a whole, was similar among the tested stocking densities (p > .05). Larviculture of C. macropomum can be successfully carried out at stocking densities of up to 50 larvae/L during the first 30 days of rearing in slightly saline water in recirculating aquaculture system.