an investigation on relative frequency of monogenean infestation in anzali lagoon fishes (hemiculter leucisculus and abramis bramaorientalis) as an indicator for contamination of pyrbazar river

anzali lagoon can be one of the most important wetlands called the world. this lagoon to support the most fish in the caspian sea is reproduced for the spawn, multiply, and sometimes live, to make the pond.much of rasht and anzali city sewage and agricultural waste area of the lagoon through rivers into the pyrbazar and increased levels of organic pollutants such as nitrite, nitrate, phosphate, oil and heavy metals to derivatives. seasonal parasite prevalence and density by organic pollutants is influenced to justify. indicators of metabolic, parasitic, or pathologic marker as a useful, economical and reliable to determine the effects of environmental contaminants are used. therefore, mainly ectoparasites as pollution indicators are used. thus, the relative frequency of contamination of monogeneanectoparasites in fish tyzcoli (hemiculter leucisculus) of native fish and sim (abramis bramaorientalis) anzali lagoon of migrant fish were investigated. five sampling stations in the anzali lagoon were done. station using the relevant tour blades per station number 30 sim and 40 number fish tyzcoli fishing was live in the central laboratory was transferred. the dactylogyrushigh number of fish that were studied about 19.4% of fish studied are infected with this parasite. gyrodactylus9.4% of fish parasites and 3.1% were infected with parasites diplozoon paradoxum. in five places, sampling, parts of anzali lagoon north central area on river water pollution caused by pyrbazar the location of contamination is high value monogenean parasites were more severe. of contamination between fish sim and tyzcoli no significant mean difference (p <0005).