Hironori Komatsu

Two new species of the genus Goneplax (Decapoda, Brachyura, Goneplacidae) from East Asia

[Two new species of goneplacid crab, Goneplax marivenae and G. megalops, are described from the Philippines and Japan, respectively. Both new species are closely similar to G. sigsbei (A. Milne-Edwards, 1880) from the western Atlantic Ocean in the form of the carapace, eyestalk, fourth ambulatory leg, and male pleopods, but can be distinguished from G. sigsbei by the form of the orbit. Both new species are also similar to G. maldivensis Rathbun, 1902, but are distinguished from G. maldivensis by the form of the male abdomen. Goneplax marivenae is most closely similar to G. megalops, but can be distinguished from G. megalops by the form of the extraorbital tooth and the male first pleopod. Deux especes nouvelles de crabes Goneplacidae, Goneplax marivenae et G. megalops, sont decrites respectivement, des Philippines et du Japon. Les deux especes nouvelles sont tres proches de G. sigsbei (A. Milne-Edwards, 1880) de locean Atlantique occidental par la forme de la carapace, les pedoncules oculaires, la quatrieme patte ambulatoire, et les pleopodes mâles, mais sen distinguent par la forme de lorbite. Les deux nouvelles especes ressemblent egalement a G. maldivensis Rathbun, 1902, mais sen distinguent par la forme de labdomen mâle. Goneplax marivenae est le plus proche de G. megalops, mais en differe par la forme des dents extraorbitales et le premier pleopode mâle. , Two new species of goneplacid crab, Goneplax marivenae and G. megalops, are described from the Philippines and Japan, respectively. Both new species are closely similar to G. sigsbei (A. Milne-Edwards, 1880) from the western Atlantic Ocean in the form of the carapace, eyestalk, fourth ambulatory leg, and male pleopods, but can be distinguished from G. sigsbei by the form of the orbit. Both new species are also similar to G. maldivensis Rathbun, 1902, but are distinguished from G. maldivensis by the form of the male abdomen. Goneplax marivenae is most closely similar to G. megalops, but can be distinguished from G. megalops by the form of the extraorbital tooth and the male first pleopod. Deux especes nouvelles de crabes Goneplacidae, Goneplax marivenae et G. megalops, sont decrites respectivement, des Philippines et du Japon. Les deux especes nouvelles sont tres proches de G. sigsbei (A. Milne-Edwards, 1880) de locean Atlantique occidental par la forme de la carapace, les pedoncules oculaires, la quatrieme patte ambulatoire, et les pleopodes mâles, mais sen distinguent par la forme de lorbite. Les deux nouvelles especes ressemblent egalement a G. maldivensis Rathbun, 1902, mais sen distinguent par la forme de labdomen mâle. Goneplax marivenae est le plus proche de G. megalops, mais en differe par la forme des dents extraorbitales et le premier pleopode mâle. ]

A new xanthid crab (Decapoda, Brachyura) from a submarine cave in the Philippines

A new species of the family Xanthidae, Gaillardiellus holthuisi , is described based on a single male from a submarine cave in Cebu, the Philippines. Gaillardiellus holthuisi sp. nov. differs from its congeners in having thickened and peculiarly curved cheliped fingers, with each immovable finger armed with a large triangular tooth. The specimen examined is preserved in the collection of National Museum of Nature and Science, Tokyo (NSMT). The size of the specimen is indicated by cb (breadth of carapace) and cl (length of carapace). Keywords: Gaillardiellus holthuisi ; NSMT; Philippines; submarine cave; Xanthidae

Two new species of the genus Heteronucia (Crustacea: Decapoda: Brachyura: Leucosiidae) from Japan

ABSTRACT Two new species of leucosiid crabs, Heteronucia toyoshioae and H. granulata, are described from the offshore banks of the Ryukyu Islands in southern Japan and the Izu Islands in central Japan. Heteronucia toyoshioae may be distinguished from all the known species of Heteronucia Alcock, 1896 by having seven tubercles on the carapace, a median triangular tooth on the sixth segment of the male abdomen, and the shape of the male first pleopod. Heteronucia granulata is similar to H. globata Sakai, 1963 and H. perlata (Sakai, 1963) from East Asia but can be distinguished by the presence of a small tubercle on the pterygostomian margin, a ridged row of granules on the branchial region, and a triangular tubercle on the posterolateral margin of the carapace.

On Merocryptoides, a Leucosiid Crab Genus (Crustacea: Decapoda: Brachyura) Endemic to Japan, with Description of Two New Species

Abstract The taxonomy of the leucosiid crab genus Merocryptoides Sakai, 1963 is revised, and two new species, M. ohtsukai and M. peteri are described from Japan. These new species resemble the type species of the genus, M. frontalis Sakai, 1963 from Japan, but can be distinguished from it by the form of the cardiac tubercle, male abdomen, male telson and first male pleopods. Merocryptoides ohtsukai is also distinguished from M. peteri by the broadly V-shaped ridge on the gastric tubercle, the lateral margin of the hepatic region not ridged and the form of the median tooth of the epibranchial margin.

Two new species of the genus Actumnus Dana, 1851 (Decapoda, Brachyura, Pilumnidae) from the Ryukyu Islands, southwest Japan

Two new species of the crab genus Actumnus Dana, 1851 (family Pilumnidae) are reported from the Ryukyu Islands, southwest Japan. Actumnus tsurukaii sp. nov. is similar to A. squamosus (Dexa0Haan, 1835), A. setifer (Dexa0Haan, 1835) and A. forficigerus (Stimpson, 1858) in possessing a poorly defined dorsal surface of the carapace with a coat of short setae, but differs in having relatively larger, fewer and more widely spaced conical granules or tubercles on the outer surfaces of the palms of both chelipeds. Actumnus uformis sp. nov. is similar to A. dorsipes Stimpson, 1858 and A. granotuberosus Garth & Kim, 1983 in having a prominently areolated dorsal surface of the carapace with a soft thick tomentum, but can be distinguished by the stronger areolation and the distinctly U-shaped protogastric region.