Myxosporean parasites of Ceratomyxa merlangi and Myxidium gadi in whiting Merlangius merlangus: a comparative epizootiological analysis based on samples from two localities off southern and northern coasts of the Black Sea

Totally 690 and 423 whiting Merlangius merlangus samples were collected from two localities off Southern (Sinop) and Northern coasts (Balaklava Bay) of the Black Sea, respectively, and examined for myxosporeans in the period from May 2011 to March 2014. Ceratomyxa merlangi and Myxidium gadi were the only myxosporean parasites identified in the content of gall bladder and their infection indices of prevalence (%) and intensity were calculated for length classes and sex of fish as well as for the seasons at both sampling localities. Overall infection prevalence of C. merlangi was 22.6% in Sinop and 27.9% in Balaklava samples while those values of M. gadi were 18.4% and 28.6% in Sinop and Balaklava samples, respectively. Both parasite species were also found to be co-existed in whiting samples. This is the first comprehensive epizootiological study yielded comparable data on C. merlangi and M. gadi infections in whiting in the southern and northern coasts of the Black Sea.