International study on <i>Artemia</i> : 32. Combined effects of temperature and salinity on the survival of <i>Artemia</i> of various geographical origin

The brine shrimp inhabits geographically isolated biotopes with specific biotic and abiotic conditions. This has resulted in various geographical strains between which marked genetica, biological and chemical differentiation exists. The response of 13 different Artemia strains to the combined effect of temperature and salinity has been studied. Experimental temperatures tested ranged from 18 to 34°C and salinities from 5 to 120 promille. Except for Chaplin Lake (Canada) Artemia , all strains showed high survival over a wide range of salinities (35-110 promille). For all strains the common temperature optimum was between 20 and 25°C. Interaction between temperature and salinity was negligible or very limited. Substantial differences in tolerance were recorded in particular at the lower end of the range of experimental salinities and at the upper end of the range temperatures. Resistance to high temperature seems to be related to the genetic classification of the Artemia strains in different sibling species. Differences, however, also exist among strains from the same sibling species. Genetic adaptation to high temperature seems to take place in Artemia . The data obtained provide a first guideline for strain selection for specific aquacultural purposes