ABSTRACT
The individual Artemia populations vary considerably with respect to their tolerance for waters of different ionic compositions. Ecological isolation among these populations occurs because of an intolerance for each other's natural habitat due to differences in lakewater chemistry. The Artemia of the New World are bisexual and with the exception of one population, belong to the A. franciscana superspecies. Temperature/salinity tolerances and optima differ among species/populations, and genetic shifts in temperature optima can be selected for both in the laboratory and in the field. A. franciscana populations outcompeted A. parthenogenetica populations in 91% of the scorable trials. A. tunisiana is the most widely distributed among these three bisexual species. A. tunisiana is found in the Mediterranean region, more specifically in Spain, North Africa, and on several of the Mediterranean Islands, including Cyprus. A. tunisiana has been collected primarily from sodium chloride lakes, as has A. per-similis.
