First Eastern Mediterranean Record of Xenoligophoroides cobitis, the Only Dactylogyrid Monogenean Infecting Mediterranean Gobies: Just Arrived or Missed the Boat?

Gobies and their ectoparasitic monogenean flatworms are promising models for species diversification because of richness. Recent decades have seen the discovery several new Gyrodactylus (Monogenea: Gyrodactylidae) on European gobies, mostly in sand goby lineage especially eastern Mediterranean. However, fauna other gobies is much less understood. Therefore, we inspected five gobiid (34 specimens, vouchered, with some representatives sequenced), sampled Greece, ectoparasites. Only specimens giant goby, Gobius cobitis, were infected; they harbored Xenoligophoroides cobitis Dactylogyridae) gills. Here, provide first record from ITS rDNA COI sequences representative this monotypic genus. Additionally, 28S was sequenced compared published data across its known distribution, suggesting clinal variation. No sister-group could be proposed, nor explain presence a single member genus due to lack sequence closely related dactylogyrid monogeneans public databases. Possible hypotheses include either ancestral long-term gobiids but “missing boat” events “Gobius-lineage”, or recent host switch non-gobiid host.