Studija infekcije parazitskim protozoama kod tri endemične vrste riba u reci zayandehrood u Iranu

Various parasites (protozoan and metazoan) can reside either inside or on the surface of the host. Pathogens or parasites do not always cause disease in fish, but may be present in a subclinical or carrier state. Some of parasites can infect all or most species of freshwater fishes. For example Ichthyophthirius multifiliis can infect almost all freshwater fish. External parasites may cause secondary fungal, bacterial and viral infections or act as carriers of bacteria, virus and other pathogens. In this study samples were collected from five stations in summer of 2010. Overall 71 native fish from 3 species had been caught from Zayandehrood River, including 18 Capoeta damascina (62.4 ± 27.5 g), 20 Chondrostoma regium (34.8 ± 10.4 g) and 33 Leuciscus Lepidus (43.7±11.9 g). Wet mount from skin and gills were prepared and studied under a light microscope, after that gills were studied with a stereo microscope. Results of our study showed that 7 out of 18 Capoeta damascina (38.88%), 4 out of 20 Chondrostoma regium (20%) and 5 out of 33 Leuciscus Lepidus (15.15%) were infected with Ichthyophthirius multifiliis. 3 out of 18 Capoeta damascina (16.66%), 5 out of 20 Chondrostoma regium (25%) and 5 out of 33 Leuciscus Lepidus (15.15%) were infected with Trichodina spp. None of 18 Capoeta damascina and 20 Chondrostoma regium (0%) was infected with Chilodonella sp. However, 2 out of 33 Leucisus Lepidus (6.06%) were infected with Chilodonella sp. In our study 3 protozoan parasites were collected from 3 species and in total Ichthyophthirius multifiliis (22.53%) was most common parasite. Environmental factors such as temperature can effects on prevalence rate of external protozoan parasites