The genus Hemionchos Campbell & Beveridge, 2006 (Cestoda: Trypanorhyncha) in Australian manta rays (Batoidea: Mobulidae)

New species of Hemionchos ( Cestoda: Trypanorhyncha) are reported from the spiral valve of the manta ray Mobula alfredi (Krefft) from the Great Barrier Reef, Queensland, representing the first record of this genus from Australian waters. Four undescribed species were identified from the spiral valve contents of a single ray. A relatively complete description is presented for H. australis sp. nov. The remaining three new species are described but as the descriptions are incomplete, they have not been named. This study suggests a much higher degree of diversity within the genus Hemionchos than hitherto suspected and that the examination of additional species of manta and devil rays will yield more new species. The genus is redefined based on the addition of new species and a key to the species is provided.

Automated summary

New species of Hemionchos were discovered in the spiral valve of the manta ray from the Great Barrier Reef, Australia, marking the first record of this genus in Australian waters. Four undescribed species were found in the spiral valve contents of a single ray. One species, H. australis sp. nov., was described in detail while the other three new species were described but remain unnamed due to incomplete descriptions. This study suggests a greater diversity within the genus Hemionchos than previously thought, and further research on other species of manta and devil rays may uncover more new species. The genus is redefined based on the addition of new species and a species key is provided.