Review of Pyragraphorus (Monogenoidea: Pyragraphoridae) and Its Position in the Order Mazocraeidea, with Descriptions of Two New Species from Carangid Fishes in Australia

Two new species of Pyragraphorus Sproston, 1946 (Mazocraeidea: Pyragraphoridae) were collected from the gills of carangid fishes: Pyragraphorus rohdei n. sp. from Trachinotus baillonii (Lacépède) off Lizard Island, Queensland, Australia, and Pyragraphorus ningalooensis n. sp. from Trachinotus botla (Shaw) from Ningaloo Reef, Western Australia, Australia, during June 2022 and March 2023. Pyragraphorus was reviewed, its diagnosis emended, and the new species described and compared with their congeners, Pyragraphorus pyragraphorus (MacCallum and MacCallum, 1913) Sproston, 1946, and Pyragraphorus hollisae Euzet and Ktari, 1970. The identification of specimens reported by Young as P. pyragraphorus from T. botla in Moreton Bay, Queensland, was corrected to P. ningalooensis. A phylogenetic hypothesis was reconstructed, on the basis of an analysis of partial 28S rDNA, including novel molecular data from the new species and from new collections of Heteromicrocotyloides megaspinosus Barton, Beaufrère, Justine, and Whittington, 2009, and Heteromicrocotyloides mirabilis Rohde, 1977 (both Heteromicrocotylidae) from Turrum fulvoguttatum (Forsskål), together with available comparable data for 76 other species representing 18 families of the order Mazocraeidea. The novel hypothesis indicated that the Pyragraphoridae and Heteromicrocotylidae, both characterized, in part, by species possessing fire-tongs-like haptoral clamps, originated independently in a larger, highly supported clade of the order that included species of the Heteraxinidae and the Microcotylidae. The Heteromicrocotylidae was found to be polyphyletic by Heterapta heterapta Unnithan, 1961, occurring independently of the 2 species of Heteromicrocotyloides. In addition, the Microcotylidae was recovered paraphyletic to the Pyragraphoridae and the Heteraxinidae was paraphyletic to the Heteromicrocotylidae. Other instances of para- and polyphyly among the familial and subfamilial taxa within the Mazocraeidea were suggested, but no family-group taxonomic changes were proposed.