Blood parasite of the genus Dactylosoma Labbé, 1894 in Marsh frog Pelophylax ridibundus (Pallas, 1771) from the north of Iran

Blood parasites of the order Adeleiorina (protozoan phylum Apicomplexa) are a diverse group of haemoparasites reported from almost all vertebrate classes. The most commonly recorded haemoparasites of anurans are species of Dactylosoma Labbé, 1894. To date, six Dactylosoma species have been described from anurans and fishes. In the present study, we used molecular characterization to identify haemoparasites detected by microscopy in blood smears of Pelophylax ridibundus, a frog in the north of Iran. Blood samples were examined from four adult individuals. Smears were prepared and stained with Giemsa. Microscopy investigation revealed that one individual was positive for blood parasites. According to morphological characteristics, it was identified as belonging to genus Dactylosoma. In genetic analyses, the blast of obtained partial 18S rRNA gene sequences showed 100% identity with Dactylosoma sp. and D. ranarum (Kruse, 1890). Phylogenetic analysis showed the Dactylosoma sp. of the present study as a monophyletic group in Dactylosoma species, clustered with Dactylosoma sp. and D. ranarum (support 80%). This study is the first report of a dactylosomatid parasite in Pelophylax ridibundus.