Ecological study of zooplankton communities in the Persian Gulf Martyrs Lake (Chitgar-Tehran) and the first report of the freshwater jellyfish Craspedacusta sp. (Cnidaria, Limnomedusae) in Iran

This study focused on zooplankton structure, biodiversity, relationship between a biotic parameters and zooplankton variation, and trophy state of the Persian Gulf Martyrs Lake (Chitgar-Tehran). Based on the lake condition, samples were collected by Juday net at the 5 stations between 2013 and 2014. This study identified 36 zooplankton taxa comprised of Arthropoda (6 genus), Protozoa (6 genus), Rotatoria (20 genus), Nematoda (1 genus), Gastrotricha (2 genus) and Oligochaeta (1 genus). Furthermore, the first record of the freshwater jellyfish Craspedacusta sp. in Iran, with size group of 15-20 mm in diameter in September is reported in the Chitgar lake. The Rotatoria abundance average was measured 61 ±18 ind.l-1 in the lake. The Nematoda, Gastrotricha and Oligochaeta taxa were measured the lowest abundance (< 1 ind.l-1) in this study. The annual average zooplankton abundance was measured as 72±18 ind.l-1. The PCA displayed, the Rotatoria Trichocerca sp. and Polyarthera sp. were dominated with high components loading, low variance and high abundance. The CCA showed, there was no correlation between Rotatoria abundance and a biotic parameters. Based on the zooplankton structure and bio-indicator, the lake situation is in the meso-oligotrophic category. Thus, it is might be increased eutrophication trend due to no management and no aquatic control in this ecosystem.