An Investigation on Species Composition and Quantitative Distribufion of Periphyton in Anzali Lagoon

The goal of study was to recognize species and distribution of peryphytons in the Anzali lagoon. Peryphytons are ecologically placed as a ring in biological chain between planktons and benthosis. They play an important filtering role in aquatic ecosystem. Fish fry of sturgeons, kutum (Rutilus frisii kutum), and many other species feed on them. The study was carried out at eleven station, in different places of Anzali Lagoon from June to January in 1996. 176 plant and 17 animal species were recognized. Plant species were consisted of 4 phylum; Chrysophyta (69 species), Chlorophyta (52 species), Cyanophyta (48 species) and Rhodophyta (7 species). Animal species of 8 phylum, Annelida (3 species), Arthropoda (4 species), Briozoa (3 species), Coelenterata (1 species), Mollusca (2 species), Protozoa (2 species), Kamptozoa (1 species) and Nematoda (1 species) were also recongnized. Replacement of animal and plant species was observed in all stations except station 4 (the nearest place to the sea) where animal species were dominant. Study on marine factors showed that Dreissena polymorpha was more dominant and had a high biomass. To continuation of montly sampling, making dynamic data bank and formation of periphyton collonies, we can get more precies and more comprehensive informations on dispersion, combination and growth speed of this group of creatures in Anzali lagoon.