The identities of Pinnotheres villosulus Guérin-Méneville, 1832, P. edwardsi De Man, 1887, and P. trichopus Tesch, 1918, with description of a new Indo-West Pacific genus of pinnotherid crab (Decapoda: Brachyura: Pinnotheridae).

The article focuses on the taxonomic clarification and reclassification of the pea crab species originally described as Nepinnotheres villosulus and Nepinnotheres edwardsi, both widespread in Southeast Asia and northern Australia. Due to the loss of the holotype of N. villosulus and morphological indistinguishability between the two species, a neotype for N. villosulus is designated, and N. edwardsi is synonymized under it. Molecular phylogenetic analyses reveal that N. villosulus is phylogenetically distant from Nepinnotheres sensu stricto, leading to the establishment of a new genus, Celotheres, to accommodate this species. Celotheres villosulus is characterized by females having a dense setal tomentum obscuring the carapace and pereopods, and it is known to inhabit ostreidan bivalve hosts across the South China Sea, northern Australia, and the eastern Andaman Sea.