Study of Planktonic Crustacean Communities (Copepoda, Cladosera) of the Arvand estuary by Scanning electron microscope

The purpose of this study was to identify and investigate the density and distribution of copepoda and cladosera and the structural analysis of their dominant species in the Arvand river by SEM (scaning electron microscope). Sampling was conducted with 50 μm mesh size plankton net at 6 stations and four times (in different seasons) with three reputation. The samples were detected by phase contrast microscopy and SEM. Totally 15 species of copepoda and 5 species of cladocera were identified in the river. The highest density of planktonic crustaceans including copepoda and cladocera with a mean density of 9481 and 3155 individuals per cubic meter was calculated in summer. These species, Acartia faoensis, Canthocalanus pauper, Subecalanus flemingeri, Labidocera acuta, which accounted for 61% of the total copepods abundance and 54% of the cladosera abundance were related to Moina macrocopa and Daphnia longisoina. The integrity of river were study using saprobic index which showed mesosaprobic-β (medium pollution) with mean 2.48 point.