The invasive freshwater medusa Craspedacusta sowerbii Lankester, 1880 (Hydrozoa: Olindiidae) in Israel

The freshwater jellyfish Craspedacusta sowerbii, native to China, has been introduced to lentic and lotic habitats in artificial and natural bodies of water, in subtropical to temperate regions worldwide. In the Middle East it has been recorded from an artificial lake in the Nile Delta, Egypt, a recreational lake in Iraq, a reservoir and a dammed lake in Turkey. The first record in Israel dates back half a century - to an aquarium at the Hebrew University in Jerusalem. Since 2003 medusae of C. sowerbii have been observed in a perennial stream flowing into Sea of Galilee - Israel's principal freshwater storage and supply reservoir. The possible impacts of a substantial bloom are discussed.