Distribution and diversity for aquaculture Planktonic of Investigation Zayanderood river development in the margin of

During  planktonic  exploration  in the  study of the construction of coldwater fish culture in Zayandehrood  riversides  during 2007-2008, it showed that  the  plankton of this river has a low frequency and diversity. Planktonic  sampling  was  carried out  at 7 stations  and  along  the river. The plankton sampling  method  was designed  to  measure, Phytoplankton were collected for a liter of water directly , for  Zooplankton  samples  30 liter  of  water  were  filtered  by 55 micron zooplankton net(Apstein net). Samples were preserved with formaldehyde at % 4 concentration for analyses in the laboratory. In phytoplankton  study  of  this  river, 4 phylum  and  25  species  have been identified. The  most commonly  observed  species  belong  to  Bacillariophyta, The most important  of  genus  this phylum were  Navicula, Cymbella and  Nitzschia. Bacillariophyta  accounts for 94.7% of the annual Phytoplankton  frequency  in  this  river. 6 Phyla  and  29  genera were identified in  zooplankton study, the  most  frequent  of  which  was  Protozoa  and  the  most  diversity  was  related to phylum Rotifera. The  results  of  zooplankton  study  show Protozoan domination with %74.2 of  zooplankton  population (Ciliophora %51.8 and  Rhizopoda %12.7) which  has  the  most  frequency. The  most  important genus of  Rhizopoda was  Difflugia, Arcella, and  Centropyxis.  establishment  fish culture  along the rivers was commonplace in world, so the development and revision of river fortunes is essential for proper exploitation  of  these  water  resources in  aquaculture, while maintaining the health of the river ecosystem necessary .