Tolerance of the shrimp Litopenaeus stylirostris, Stimpson 1894, to environmental stress: interindividual variability and selection potential for stress-resistant individuals

摘要

Our study showed that osmoregulatory capacity (OC) of shrimp from the same clutch displayed interindividual variability. When environmental salinity decreases. this variability increases. Thus, at isoosmotic point (sea-water salinity 26), the coefficient of variation calculated for measured OC was 2.7%. whereas it was 8.2% for sea-water salinity approximate to1.5. In terms of haemolymph osmolality, the interindividual difference can reach up to 45.8%, for the same water salinity level. The mean OC of individuals that have survived a series of salinity and temperature shocks is significantly greater than the mean value recorded within their original population. This increase in OC was maintained beyond the one or two moulting periods that these shrimp experienced during our experiment.