The occurrence of Anostracans—Fairy shrimps Branchipus schaefferi in vernal pools of Bahrain

摘要

The occurrence of a native species of fairy shrimp (Anostraca) in the Kingdom of Bahrain is documented for the first time. The appearance of adults depends on rainfall events which are rare. These organisms survive by producing dormant cysts that survive the dry period between rainfall events. The size of the population differences between sexes, life cycle duration, tolerance to the fast retreating vernal pools and survival under the laboratory conditions are discussed. Multi-modal population density indicated two peak hatching events. Daily size frequency distribution revealed the occurrence of smaller sized individuals throughout the adult activity period. From 1995 and 2001 salinity level in one pool increased. This may affect the vegetation of this area.