Parasites as biological tags of divergence of black-striped pipefish, Syngnathus abaster (Actinopterygii: Syngnathiformes: Syngnathidae), populations in their natural and acquired range

The presently reported study was intended to describe the current range of an Atlanto–Mediterranean fish, black-striped pipefish, Syngnathus abaster Risso, 1827, in Ukrainian waters and analyze biological tags (size parameters parasites) its different populations. parasitological survey carried at five localities, including one marine site, two deltaic zones, localities middle Dnipro basin. provides comprehensive new data on parasites pipefish Ukraine, with supporting newly acquired freshwater range. A total 21 parasite species (taxa) were revealed. Several recorded for first time this host, i.e., Trichodinella epizootica (Raabe, 1950); Trypanosoma sp.; Bothriocephalus scorpii (Müller, 1776); Progrillotia dasyatidis Beveridge, Neifar et Euzet, 2004; Ophiotaenia europaea Odening, 1963; Cryptocotyle jejuna (Nicoll, 1907); Metorchis xanthosomus (Creplin, 1846); Tylodelphys clavata (von Nordmann, 1832); Holostephanus luehei Szidat, 1936; Contracaecum rudolphii Hartwich, 1964; Mothocya epimerica Costa Hope, 1851; Unionidae gen. sp. Formation species’ component community depends entirely environmental factors, local features forming due 1) presence “marine” unicellular (ciliates) (10‰–17‰ salinity) only, as a refraction relative stenohalinity ( Trichodina rectuncinata Raabe, 1958), findings ciliate locations representing examples successful osmoconformation partidisci Lom, 1962); or 2) multicellular abiotic/biotic conditions that allow completion complex life cycles, such those trematodes (freshwater/marine mollusks obligate hosts) cestodes invertebrates intermediate hosts marine/freshwater vertebrates definitive hosts).