INTERNATIONAL STUDY ON ARTEMIA .52. INCUBATION OF ARTEMIA CYST SAMPLES AT HIGH-TEMPERATURE REVEALS MIXED NATURE WITH ARTEMIA-FRANCISCANA CYSTS

We present evidence that incubation of brine shrimp Artemia encysted e mbryos (cysts) at high temperatures (36-37-degrees-C) suppresses hatch ing of cysts from a parthenogenetic population, while at the same time allowing cysts of the New World bisexual species (A. franciscana) to hatch. This approach is used to verify the presence of contaminating f oreign material from the New World in natural cysts population of Old World A. parthenogenetica, A. sinica, A. urmiana and A. tunisiana. We demonstrate that high temperature incubation can be routinely applied to cysts from natural Artemia populations occurring adjacent to fish a nd shrimp hatcheries, to determine the extent and source of contaminat ion.