Paratrypaea Komai & Tachikawa, 2008 (Decapoda: Axiidea: Callianassidae): more than two or three species

Abstract

Abstract Paratrypaea Komai & Tachikawa, 2008 has for more than a decade been thought to contain only two species, both widespread throughout the Indo-West Pacific, or briefly three species. Molecular studies using mitochondrial 16S rRNA and 12S rRNA plus nuclear H3 and 18S rRNA genes, repeated here with samples from more individuals, have shown well separated clades within the genus. Morphological examination has found differences, especially in the form of the adult male cheliped, between the clades leading to the conclusion that Paratrypaea comprises at least eight species of which four are new and described herein. Not all closely related clades could be morphologically distinguished. Some species are narrowly and others widely distributed. The species are: P. baliensissp. nov. from Indonesia; P. bouvieri (Nobili, 1904) from the Red Sea and Indian Ocean; P. chichijimaensis (Sakai, 2015) comb. nov. from Japan; P. dworschakisp. nov. from the Hawaiian Islands; P. maldivensis (Borradaile, 1904) from the eastern Indian Ocean, Papua New Guinea, and possibly western Pacific; P. niuginiensissp. nov. from Papua New Guinea; P. rectangularis (Ngoc-Ho, 1991) from French Polynesia to the Red Sea; and P. rempiensissp. nov. from Papua New Guinea. A published partial 16S sequence from Japan has provided evidence of one more species than those proposed here. Paratrypaea cristata (Borradaile, 1910) comb. nov. remains a species inquirenda.