First report and Molecular identification of Rhadinorhynchus sp (Acanthocephala), based on 18S Ribosomal DNA Gene Sequences

Acanthocephala are a group of invertebrate and are arthropod and vertebrate parasites with cosmopolitans distribution. These parasites cause of disease in the vertebrates like fishes. The invistigastion of these parasites is essential for the identification and preventation of infection. One method of organism taxonomy and identification is molecular identification along with morphology. In this study gastrointestinal parasites of 54 tuna fishes(Thunnus albacares ) were studied in 2012. Acanthocephala which was a dominant parasits in these fishes, were separated. Acantocephalan rDNA was extracted according to the modified CTAB method and nucleotide sequence studied in SSU_rRNA region. Iranian species sequences were compared with 2 species of Acanthocephala from GenBank. Phylogenetic relationship among species assessed by ML analysis. Result showed monophyly within Acanthocephaa classes. Iranian species was sister group with Rhadinorhynchus sp and with 99% Bootstrap supported. Iranian species was belong toorder of Echinorhynchida. The results of species morphology analysis were agreed with molecular results. This is the first report of Acanthocephalan parasite of tuna fish from Oman sea.