لیلا پیروزی

The Lakes and surface water reservoirs are considered as the most important sources of freshwater. These ecosystems are used for different purposes and create an important habitat for aquatic organisms, especially plankton and fish. In this regard, this study was carried out to investigate biological communities of phytoplankton and zooplankton from the Garan Dam Lake, Marivan. Sampling was done seasonally during 2016-2017 at 4 stations in different situations. According to the depth of the station, only the surface layer was sampled in the entrance stations including stations 1 and 4, and three layers (surface and middle layers and 1 meter above the bed) were sampled in stations 2 and 3 located in the body of the dam lake. Then, the water samples were fixed in 4% formalin and transferred to the laboratory for further studies. Mass density calculation and identification of phytoplankton and zooplanktons was done based on valid identification keys. A total of 31 genera, 28 families and 6 branches were identified. The results showed that the highest frequency of phytoplankton was observed in spring  and their lowest in autumn. Totally, 2 branches, 9 families and 16 genera and species were identified from zooplankton communities, 9 species and genera belonging to Rotifera and 7 species and genera belonging to Arthropods. Also, the highest and lowest density of station 1 was observed with 59.5±4.5 and station 2 with 16.36±1.44 (cells/ml). The results of the presence of large zooplankton i.e. Ascomorpha saltan, Daphnia magna and Cyclops sp. (high filter feeding power) showed, they can be a serious competitor for planktivorous fishes and the primary production of the lake, and it is necessary to balance their population with zooplanktivorous fishes.

Caddisfly sampling conducted during August 2021 from the Gurgur River in the Sabalan Mountains, Ardabil province, Iran, revealed the first record of Glossosoma unguiculatum Martynov, 1925 for Iran. Previously, this species had only been known from few localities in Turkey, the Caucasus and Kazakhstan. The morphology of male genitalia in the collected specimens generally corresponds to the described species, with the exception of a less incised ventral margin of the abdominal segment IX in ventral view, which may be attributed to geographical variability. This discovery marks the second species of the genus Glossosoma Curtis, 1834 found in Iran.