Effects of different salinities on juvenile growth of Gammarus aequicauda (malacostraca: Amphipoda)

Abstract

Gammarus aequicauda is a euryhaline amphipod that is a common inhabitant of brackish environments of the Mediterranean Sea. In the Ebro delta, the population density of G. aequicauda is highly variable throughout the year. The main objective of this study is to investigate the effect of salinity on the growth of G. aequicauda juveniles. G. aequicauda embryos and juveniles can survive and grow in the laboratory between 2psu and 40psu salinity, depending on the previous acclimation period for the reproductive individuals. Adults acclimated at 34psu produced embryos and juveniles that survived and developed at salinities between 9psu and 40psu; adults acclimated at 9psu produced embryos and juveniles that could develop in oligohaline conditions. The lower growth rate values were 10.9μmd -1 and 13.5μmd -1 at 40psu and 2psu, respectively, with the higher values of 18.0μmd -1 and 18.5μmd -1 at 19 and 34psu, respectively. © 2011 Ldia Delgado et al.