Growth of juvenile common snook (Centropomus undecimalis Bloch, 1792) reared at different temperatures and salinities: Morphometric parameters, RNA/DNA, and protein/DNA ratios

ABSTRACT

We investigated the growth of juvenile common snook (Centropomus undecimalis) reared at 25°C and 28°C and salinities of 0.3, 15, and 32 g L⁻¹. Total length, weight, RNA/DNA, and protein/DNA ratios were determined after 90 days of experiment. Higher growth was observed at 28ºC compared with 25°C, at the same salinity. At 28°C and 15 g L⁻¹ salinity, the weight (25.14 g) of juveniles was twice that of the juveniles reared at the lower temperature. At different salinities, only higher temperature affected growth, with higher weight values obtained at 15 g L⁻¹ in comparison with 0.3 and 32 g L⁻¹. Length was similar at 0.3 and 15 g L⁻¹. The RNA/DNA ratio was greater in juveniles reared at a salinity of 15 g L⁻¹ when compared with 0.3 and 32 g L⁻¹. This study shows that the combination of higher temperature and intermediate salinity promotes better growth of common snook juveniles.

KEYWORDS:

• Aquaculture
• biochemical parameters
• environmental conditions
• euryhaline fishes

Acknowledgments

This work was supported by the CNPq (Conselho Nacional de Desenvolvimento Científico e Tecnológico), Brazil. The authors would like to thank Jonathan Moorhead, MSc, James Cook University, Australia, for helping improve the clarity of the manuscript.