تغييرات فون انگلي كپور معمولي Cyprinus carpio (Cypridiae:OSTEICHTHYES) در طي مهاجرت آن بين بخش جنوبشرقي درياي خزر و آب شيرين

Parasites Fauna Changes of Common Carp Cyprinus carpio (Cyprinidae: Osteichthis) during itʹs migration between Caspian Sea and freshwater

The present investigation was carried out to elucidate parasites fauna changes during migration of common carp (Cyprinus carpio) from Caspian Sea (salinity 13 ppt) to rivers for propagation purposes. In this survey external parasites (Protozoa and Monogenea) and some endo-parasites (Cestoda and Digenea) are investigated. The part of the research confined to Dactylogyrus spp. found in both environments ides Caspian sea or rivers flowing into it. Our examination shows that the common carp is infected by five Dactylogyrus in both freshwater bodies and rivers in Iran. These are included; D. extensus, D. anchoratus, D. achmerowi, D. sahuensis and D. vastator. Whereas adult fish obtained from Caspian Sea was found to be infected only by two species namely D, extensus and D. anchoratus. On the base of the present investigation we can come to conclusion that most part of the Dactylogyrus spp. infected common carp in freshwaters can not tolerate Caspian Sea environment and disappear soon after migration to Caspian Sea. It is also concluded that external Holotrichia for instance (Ichthyophthirius multifiliis, Chilodonella and Trichodina) found in the present survey are mainly riverine and unable to survive in Caspian Sea environment. While Ichthyobodo necator could live in both fresh and marine environment. In this paper we are trying to elucidate parasites fauna changes in both environments and their ecological relationship are discussed. Vet.J.of Islamic.Azad. Univ., Garmsar Branch. 4,4:159-163,2008.