The objective of this work was to estimate the sustainable biomass of pirarucu Arapaima gigas (Cuvier, 1829) juveniles kept in small volume net cages. During 200 days four 1-m³ net cages were stocked with 21 fish/cage and had an initial total biomass of 0.84±0.14 kg (21 fish/cage). The net cages were placed in a 50-m² pond with constant water flow. Conditioning factor, feed conversion, specific growth rate and gain showed that the sustainable biomass of pirarucu juveniles for intensive rearing in 1-m³ net cages was approximately 29 kg. Fish length at the end of the trial, in relation to the reduced net cage space, was a limiting factor to obtain good biological indices.
Arapaima gigas; fishes; feeding; growth; fish culture
