Speciation and specificity of acanthocephalans. Genetic and morphological studies of Acanthocephaloides geneticus sp. nov. parasitizing Arnoglossus laterna (Bothidae) from the Mediterranean littoral (Sète-France)

SUMMARYAcanthocephaloides geneticus sp.nov. is described from Arnoglossus laterna (Bothidae) from the Mediterranean littoral (Sète-France). The new species most closely resembles Acanthocephaloides propinquus (Dujardin, 1845) Meyer, 1932, whose type host is Gobius niger (Gobiidae). A genetic comparison of the parasites collected from these two Teleostean fishes has confirmed the value of morphological differences which seemed too slight to raise the populations to species status.