Production of live bait-shrimp (Farfantepenaeus paulensis) in cages at varying stocking densities

Abstract

In Brazil’s southern and southeastern coast, sport fisheries have a large demand for live bait-shrimp that is usually not met by local fishermen. The production of 4-5 g shrimp in cages may therefore provide a promising alternative to fill this gap. Unfortunately, studies defining adequate management guidelines for the production of live bait-shrimp in cages are not yet available. In this study, the influence of stocking density on the survival, growth and food conversion ratio (FCR) of the shrimp Farfantepenaeus paulensis reared in cages was evaluated. The trial lasted 42 days and assessed three stocking densities (50, 100 and 200/m²) of F. paulensis juveniles (mean initial weight of 1.04 g). Final survival and weight of shrimp reared at 50, 100 and 200/m² were 94.1, 94.6 and 59.2%, and 6.0, 5.0 and 4.3 g, respectively. Survival and final weight of shrimp were negatively related to density. FCR was not significantly different between treatments but tended to increase at higher densities. The present results indicate that the production of F. paulensis in cages is feasible at all densities tested, but as rearing 200/m² will produce a larger number of bait-sized juveniles. This stocking density may be recommended when a rearing site presenting optimal environmental conditions is available. The production of live bait-shrimp in cages may become an interesting source of income for artisanal fishermen and farmers living near estuarine areas in Brazil and elsewhere.