Distribution and species diversity of Bacillariophyta (Diatoms) and their environmental significance in aquatic life in Anzali wetland ecosystem

This study was carried out in 27 study stations in Shijan, Siakishim, Abkenar, Hendekhaleh and Rogaha(River outlets), during conducting research hydrology and hydrobiology and preparing Atlas of plankton in the Anzali wetland during the years (1376)1997 from (1393)2014. Sampling was done by (P.V.C) tube, The samples were fixed with 4% formalin and then transferred to the laboratory and after quantitative and qualitative studies with inverted microscope were taken picture them by Nikon Labophot microscop. For phytoplankton (1 liter of water sampels) were Collected alive with (p.v.c) tube (lenth , 2 m) and transfer to laboratory. samples were analyzed under a invert Microscope and then separate with Pasteur pipette and photography from different side by Nikon Labophot microscop. In total, 39 genus and 87 species were identified in the Bacillariophyta. This phylum includes a Class called Bacillariophyceae and 2 important order called Centrales and Penales, commonly referred to as "Golden- Brown Algae". The most abundant Genus of Bacillariophyta are Synedra ulna, Cyclotella meneghiniana, Navicula cuspidata, Diatoma vulgare, and Nitzchia acicularis. The members of this category are mostly Psychrophilic in autumn and winter, it is dominated by a large variety, but in warm and temperate seasons, especially in the most of the Anzali wetlands are located in the siakishem and mainoutlets, but most of their distribution are in the Abkenar area.