New material recently collected in French Polynesia provides evidence of three species of Macrophthalmus : Macrophthalmus convexus Stimpson, 1858, from the Society Islands ; M. consobrinus Nobili, 1906a, endemic to the Gambier Islands (usually considered a junior synonym of Macrophthalmus parvimanus Guérin-Méneville, 1834) ; and M. serenei Takeda et Komai, 1991, from the Tuamotu Islands. Macrophthalmus parvimanus and M. convexus are two sibling species, with sometimes a particular, distally pointed first pleopod. This special pleopod form, herein called indo-malaysian, allows the distinction of four groups : typical M. parvimanus, restricted to the western Indian Ocean ; indo-malaysian M. parvimanus, that could be M. convexus kempi Gravely, 1927, but this material has not been re-examined ; typical M. convexus , mainly distributed in the western and central Pacific ; and indo-malaysian M. convexus. For the moment, because of the existence of aberrant specimens from Hong Kong and the Philippines, belonging to a fifth group, and the variation of the shape of the pleopod in some lots, we have not given a specific status to these indo-malaysian forms.
Crustacea, Decapoda, Brachyura, Ocypodidae, Macrophthalmus, French Polynesia, Taxonomy.