Effect of stocking density on growth and survival of the prawn Macrobrachium tenellum, cultured in a recirculating aquaculture system

Abstract

The stocking density of the freshwater prawn native to the Mexican Pacific coast, Macrobrachium tenellum , has not been evaluated in a recirculating aquaculture system. M. tenellum prawns with an average wet weight of 1.71 ± 0.11 g were reared for 60 days at three stocking densities (T1 = 10 ind m -2 ; T2 = 15 ind m -2 ; T3 = 20 ind -2 ), in nine (1 m 2 ) tanks connected to a recirculating aquaculture system inside a greenhouse. Average individual weight gain (AIWG), biomass weight gain (BWG), specific growth rate (SGR), food conversion ratio (FCR) and survival rate (SR) were determined. Stocking density affected the BWG and SR. The lowest BWG was observed at the highest density (T1, 20.70 ± 4.75 g m -2 ; T2, 20.75 ± 4.72 g m -2 ; T3, 11.31 ± 3.65 g m -2 ), although weight per area unit increased with densities. SR decreased with increasing density (T1, 77.77 ± 9.62%; T2, 59.25 ± 12.83%; T3, 44.44 ± 4.81%). Other parameters did not show a difference between densities, with a maximum average individual weight at T2 (5.41 ± 1.14 g). The overall results suggested that stocking density affected the productivity and survival but not the individual growth of juvenile M. tenellum prawns cultured in a recirculating aquaculture system.