A new species of Hymenosoma Desmarest, 1823 (Brachyura: Hymenosomatidae) from Mozambique, with diagnoses and a key to species of the genus

Hymenosoma Desmarest, 1823 is here confined to seven species from southern Africa and Madagascar, one described herein, Hymenosoma luriosp. nov. from Mozambique. Hymenosoma luriosp. nov. is unique in having the male posterior thoracic lobes oval with a short stalk. Evolutionary relationships between the new species and five other species of Hymenosoma are reconstructed from sequences of the COI gene, and another tropical species, H. projectum Dawson & Griffiths, 2012, is identified as the sister taxon. Each species is diagnosed and a key to differentiate them is given. Three species of Hymenosoma described from New Zealand and Australia are excluded from this genus.