Salinity and temperature tolerance of juvenileMesopodopsis orientalis: laboratory studies

Separate and combined effects of changes in salinity and water temperature on the survival of laboratory hatched juvenileMesopodsis orientalis were investifated. Full strength seawater (35) was not favorable to juvenile survival. Salinities down to 10% seawater were tolerated when subjected to sudden exposure, but salinity acclimation increased juvenile ability to tolerate even fresh water. Water temperatures tolerated by the animals ranged from 12°C to 33°C. Salinities of 30% to 60% seawater and water temperatures of 22°C to 28°C were most favorable to the juveniles. Experimental results were compared with field observations and a relationship between the salinity and temperature of seawater and abundance of juveniles in May to June, and November to January in Bombay coastal waters (west coast of India) was established. Seawater of reduced salinity was found to be a major factor for occurrence of juvenileM. orientalis in abundance.