The plankton of the Anzali Lagoon and coastal waters of the Caspian Sea

The determination and identification of plankton species in the Anzali lagoon was carried out through a period of two years in 27 stations in the Shejan, Sakishima, Abkenar, Hendekhaleh andmain outlets of this lagoon from 1997 to 1999. The results of this study reveal that there are Totally 6 phyla of Phytoplankton that include, 134genera and 278 species of which 56 genera and 107 species belong to Phylum Chlorophyta, 39 genera and 87 species belong to Phylum Bacillariophyta (Diatoms), 2 genera and 2 species belong to Phylum Xanthophyta, 4 genera and 4 species belong to Phylum Chrysophyta, 6 genera and 34 species belong to Phylum Euglenophyta, 8 genera and 11 species belong to Phylum Pyrrophyta, 18 genera and 32 species belong to Cyanophyta and one genus belongs to phylum Rhodophyta. It is evident from these results that Cyanophyta and Bacillariophyta showed the highest density among Phytoplanktons with the highest Aboundance found in the Abkenar and southern Hendekhalehregions. Highest density of Cyanophyta was observed in Abkenar region during the end of spring and beginnings of summer. Bacillariophyta was observed all-round the year throughout the Anzali lagoon being more aboundant the end of autumn, winter and spring. Other phyla showed similar population densities throughout the year. study of Zooplanktons revealed the presence 11 phylum that include 133 genera and 211 species Anzali lagoon of which 10 genera 22 species belong to phylum Rhizopoda ,4 genera 4 species belongto Phylum Actinopoda, 32 genera 41 species belong to Phylum Ciliophora, one genus and one specie belong to Phylum Porifera, 3 genera belong to Phylum Coelantrata, 2 genera and 2 species belong toAnnelida, 2 genera 2 species belong to Phylum Platyhelminthes, 36 genera and 90 species belong toPhylum Rotatoria, one genus and one specie belongs to Phylum Tardigrada, 19 genera and 32 species belong to Phylum Arthropoda (order Cladocera), 7 genera and 11 Species belong to Class Copepoda, in Class Cirripedia and Ostracoda and Diptera(Family Chironomidae) each of them consisting of onegenus, 2 genera and 2 species belong to Class Archnida and in phylum Mollusca Class Bivalvia one genus was identified. It is evident from the present study that Rotrtoria was dominant in southern Hendekhaleh and Abkenar regions and the main outlets wherease Protozoa showed the maximum density in Shejan and Siakishem regions. Highest density of Zooplankton were observed in Hendekhaleh and Abkenar regions in end of Spring and during summer whereas all regions showed similar densities during the other seasons .