title: Levels of infection and seasonal occurrence of Gyrodactylus alviga (Monogenea: Gyrodactylidae) on the whiting Merlangius merlangus off the Turkish and Russian coasts of the Black Sea.
abstract: Gyrodactylus alviga is a generalist species reported in many Black Sea fish species, but whiting is known to be its main host. It is the only monogenean parasite that has been reported so far on the skin, fins and gills of whiting Merlangius merlangus in the Black Sea. A total of 690 fish from Turkey and 423 fish from Russia were examined to detect parasites. Infection indices of prevalence, mean intensity and mean abundance values were calculated for length classes and sex of fish, as well as for the seasons. There is a gradual increase in infection indices in relation with increasing host length classes and there are higher infection indices on female fish. Furthermore, despite lower prevalence indices in spring and winter, higher parasite intensity values were determined in these seasons. It is concluded that larger fish provided more space and food for G. alviga, and female fish were more parasitized as they were more active in searching for food, which enables the parasite to switch between hosts. In addition, winter and spring were more appropriate for reproduction of G. alviga.
authors.affiliation: Sinop University, Faculty of Fisheries and Aquatic Sciences,57000Sinop,Turkey.
authors.forename: A
authors.initials: A
authors.lastname: Özer
authors.affiliation: O.O. Kovalevsky Institute of Biology of the Southern Seas,2 Nakhimov av.,299011Sevastopol,Russia.
authors.forename: Y
authors.initials: Y
authors.lastname: Kornyychuk
authors.affiliation: Sinop University, Faculty of Fisheries and Aquatic Sciences,57000Sinop,Turkey.
authors.forename: T
authors.initials: T
authors.lastname: Öztürk
authors.affiliation: O.O. Kovalevsky Institute of Biology of the Southern Seas,2 Nakhimov av.,299011Sevastopol,Russia.
authors.forename: V
authors.initials: V
authors.lastname: Yurakhno
mesh_terms: D000818:Animals; D059038:Black Sea; D049628:Body Size; D002590:Cestode Infections / Q000453:epidemiology / Q000469:parasitology / Q000662:veterinary*; D005260:Female; D005393:Fish Diseases / Q000453:epidemiology* / Q000469:parasitology*; D048388:Gadiformes / Q000033:anatomy & histology / Q000469:parasitology*; D008297:Male; D010986:Platyhelminths / Q000302:isolation & purification*; D015995:Prevalence; D012426:Russia; D012621:Seasons; D012737:Sex Factors; D014421:Turkey