Tolerance to salinity and its effect on development of velifera molly Poecilia velifera (Regan 1914)

Abstract

ABSTRACT Velifera molly (Poecilia velifera) has an ecophysiological interest related to euryhalinity. To evaluate its tolerance and performance in different salinities, and the ability to be reared at diverse locations, Median Lethal Salinity (LS50) and growth performance were investigated. In experiment 1, 120 juveniles were tested through direct transfer to salinities 0, 24, 48, 60, 72, and 78 psu for 96 h. In experiment 2, 160 juveniles were gradually acclimatized to salinities 0, 12, 24, and 36 psu. The experiment was conducted using recirculation aquaculture systems (RAS) for 75 d. LS50-96 h was estimated at 71.1 psu and safe salinity at 7.1 psu. The final weight, weight gain, and feed intake had an inverse relationship to salinity, reflecting the sublethal effects. The apparent feed conversion rate was directly related to salinity, presented a better performance in freshwater conditions. There was no mortality in experiment 2, allowing the species to be maintained for long periods in the analyzed salinities.