The widespread Indo‐West Pacific ghost crab, Ocypode ceratophthalmus (Pallas, 1772) is found to be a species‐complex containing three distinct species. An Indian Ocean form, O. celadon sp. nov. occurs along the shores of East Africa, thence becoming an insular species spreading eastwards as far as Christmas Island. A central Indo‐West Pacific species, O. ceratophthalmus is found from about Pakistan eastwards to Fiji, north to the southern part of the main islands of Japan and south down the coasts of Australia, and is the dominant species along the continental beaches throughout the region. O. urvillii Guérin, 1829, is newly raised from synonymy for an insular Pacific Ocean form that extends from Hawai’i and Clipperton Island in the central East Pacific, westwards into the northeastern Indian Ocean as far the Cocos (Keeling) Islands. A mitochondrial genetic study from cytochrome c oxidase subunit 1 (COI) supports the recognition of these three species. Each species can be relatively easily separated by claw characters, including the stridulatory crests on the major chela, the form of the male first gonopods (G1), the live colours and patterns, and other characters related to granulation and spination.
Davie et al. (Thu,) studied this question.