A review of the Arhythmacanthidae (Acanthocephala) in Australia with the descriptions of a new genus and 6 new species

ABSTRACT Twenty-eight Australian fish species were infected with 18 taxa of Arhythmacanthidae; 11 characterised to species, 4 to genus and 3 to family. Diagnoses are provided for the genera Heterosentis, Hypoechinorhynchus, Paracanthocephaloides and Yamagutirhynchus n. gen. Heterosentis has four Australian species: H. hirsutus Pichelin & Cribb, 1999, H. paraplagusarium (Nickol, 1972), H. plotosi Yamaguti, 1935, H. lisitsynae n. sp., defined by a proboscis armature of 14–16 rows of 8–9 hooks, 4 large, 4–5 spiniform, and three indeterminate species, two from Western Australia, one from Queensland. Hypoechinorhynchus is represented by Hy. robustus Pichelin, 1999 and Hy. alaeopis Yamaguti, 1939. Paracanthocephaloides is represented in Australia by one indeterminate species and three new species: P. bartonae n. sp. has an armature of 14–16 rows of 3 large, 7 spiniform hooks; P. hustoni n. sp. 12 rows of 5–6 hooks, 2 large, 3–4 spiniform; P. shamsiae n. sp. 12 rows of 5–6 hooks, 2 large, 3–4 spiniform. Paracanthocephaloides cabelleroi (Guptar & Fatma, 1983) is returned to the genus Heterosentis. Paracanthocephaloides golvani Chandra, Hanumantha-Rao & Shyamasundari, 1984 is moved to the genus Gorgorhynchoides as G. golvani n. comb. Yamagutirhynchus n. gen. has a cylindrical proboscis with an expanded middle region. Yamagutirhynchus lymberyi n. sp. and Y. elliotae n. sp. both have proboscis armatures of 10 rows of 4–5 hooks; for Y. lymberyi the largest hooks are 42.5 μm long; for Y. elliotae, 51 μm.