Effect of temperature and density on growth of spotted sand bass Paralabrax maculatofasciatus juveniles reared in the laboratory

Abstract

A growth trial was conducted to determine the most appropriate temperature and fish density for rearing juvenile spotted sand bass Paralabrax maculatofasciatus under laboratory conditions. The experiment followed a 3 X 2 factorial design with three temperatures (24, 27, and 30°C) and two densities (266 and 400 fish/m3), with three replicates per treatment. Juveniles (mean weight 2.1 g) were fed a semi-moist diet (56% protein and 23% lipids) for 40 days, residing in tanks containing 30 L seawater within an open flow system under laboratory conditions. No effects on survival resulted from these temperatures and fish density conditions were noted. The greatest growth was observed at 27°C and 400 fish/m3, while fish reared at 24°C and 400 fish/m3 and 30°C and 400 fish/m3 had the least growth. The percent apparent daily feed consumption (%ADFC) was significantly different between the two different densities of fish reared at 27°C, but not at the lower or higher temperatures. Feed conversion ratio values were significantly different between fish grown at the intermediate (27°C) and the lower (24°C) temperatures, but not at the higher (30°C) temperature. Therefore, the most appropriate condition for growth of juvenile spotted sand bass cultured in laboratory is 27°C and 400 juvenile fish/m3 (equivalent to 0.84 g/L of initial biomass).