The Aral Sea has become increasingly saline since 1960, resulting in decimation of the aquatic biota. Of the 11 ostracod species known to have been alive in the Aral Sea 30 years ago, only one, the euryhalineCyprideis torosa,lives there today. Recent research has suggested that this species has survived because it is capable of strong hypo–osmotic regulation. The Quaternary history of the sea shows that there have often been water–level fluctuations, but recent dramatic environmental changes have had particularly severe consequences on the ostracod fau