First Molecular Data on Myxobolus episquamalis (Myxozoa: Myxosporea) Infecting the Scale of Grey Mullet (Mugil cephalus) from Turkey

Objective: The aim of the present study was to show the morphologic and molecular characterization of Myxobolus species in grey mullet (Mugil cephalus) caught from the Black Sea coasts of Turkey. Methods: A total of 104 grey mullets caught from Turkish Black Sea coasts were obtained from fish markets between November 2017 and February 2018 and were examined for the presence of Myxobolus by using morphological and advanced molecular diagnostic methods. Results: Totally, three out of 104 fish specimens were found to be infected with large and white coloured plasmodia and the prevalence was determined as 2.8%. The myxospores were morphologically identified as Myxobolus episquamalis, confirmed by using sequence analyses of their 18S rRNA gene regions. The shape of myxospores was oval and they were 8.6 (7.8-9.4) µm in length, 6.7 (6.1-7.3) µm in width and 4.7 (4.1-5.3) µm in thickness. Measuremenst of two pyriform polar capsules were 4.2 (3.7-4.6) µm in length ve 2.2 (2.1-2.4) µ m in width. The length of polar filament was determined as 27-51 µm. Nucleotide sequences of the 18S rRNA gene of the ES-2018-ERU isolate (MK012069) found in our study showed 99.8% and 100% similarity with M. episquamalis isolates submitted to GenBank from Tunisia (AY129312) and South Korea (JF810537; KC733437), respectively. Pairwise genetic distance (%) between ES-2018-ERU isolate and the other Myxobolus species which were identified in mullets from various countries were determined as 9.9-14.8%. Conclusion: This study provides first molecular Conclusion: This study provides first molecular data on M. episquamalis found in the scale of the grey mullets (Mugil cephalus) from Turkey.