More complex animals like fish, amphibians, and marine snakes can't survive in the Dead Sea. But mats of
bacteria prokaryotes, mainly in the domain Archaea [note: this was misidentified in previous versions of this article, thanks DNALX], survive in the freshwater-spouting craters. Says National Geographic: "The top of the springs' rocks are covered with green biofilms, which use both sunlight and sulfide—naturally occurring chemicals from the springs—to survive. Exclusively sulfide-eating bacteria coat the bottoms of the rocks in a white biofilm." There's no record of this kind of bacteria ever surviving in this kind of condition--saltwater bacteria of this type can't survive in freshwater, and vice versa, yet here's bacteria that survives in both.