DISTRIBUTION AND ABUNDANCE OF THE INVASIVE CTENOPHORE MNEMIOPSIS LEIDY IN THE LITTORAL WATERS OF THE CASPIAN SEA, IRAN

In this study, spatial distribution of the invasive ctenophore Mnemiopsis leidyi in the littoral waters of the Caspian Sea was evaluated using data collected at stations during the spring 2002 cruise. The average and maximum biomass of M.leidyi were 21.38 and 108.42gwet weight per m2, respectively. The average biomass of M.leidyi was 32.6g wet weight per m2 in the Iranian coastal waters whereas it was 24.99, 9.83 and 0.9g met weight per m2 in Azerbaijan, Turkmenistan, and Russia respectively. The maximum size of the ctenophore was 16-20mm, and the bulk of individuals (97.2%) were smaller than 10mmin length.