An integrative taxonomic investigation of the diversity of digenean parasites infecting the intertidal snail Austrolittorina unifasciata Gray, 1826 (Gastropoda: Littorinidae) in Australia.

We investigated for the first time the digenean parasites of Austrolittorina unifasciata Gray (Gastropoda: Littorinidae), a periwinkle snail inhabiting the rocky shores of Australia. Here we present detailed morphological descriptions and molecular data (sequences for the mitochondrial cox1 and the nuclear 28S rRNA gene) for the cercariae and intramolluscan stages of the digenean parasites found. Five species, one each of the families Notocotylidae Lühe, 1909, Gorgocephalidae Manter, 1966 and Philophthalmidae Looss, 1899, and two of the family Renicolidae Dollfus, 1939, were recorded and characterised molecularly. Phylogenetic analyses at the superfamily level provided evidence for the familial and generic affiliation of the species and their relationships with congeners. This study is the first to provide data on the life cycle of a species of the family Gorgocephalidae, a parasite of kyphosid fish for which only adult stages had, thus far, been described. The relatively high prevalence of this species allowed mapping of the cox1 haplotype distribution of Gorgocephalus sp. Aus along the southern coast of New South Wales.