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The Brachyura of New Caledonia
... Today, the number has grown substantially to 800 species and 74 families, and some 70 technical articles have been published as a consequence of the list ( Ng et al. 2017f). Similar checklists of the brachyuran fauna of New Caledonia and the Hawaiian islands have been similarly invaluable in catalysing research of particular faunas (Richer de Forges & Ng 2006;Castro 2011, respectively). ...
An annotated checklist of the marine brachyuran crabs occurring in India is compiled from published literature and augmented by collections between 2005 and 2015. A total of 910 species belonging to 361 genera and 62 families are herein listed from Indian waters. Specimens representing 130 species were obtained from Gujarat state during 2005 and 2015, of which 23 are new records to Gujarat state and two species are reported for the first time from the west coast of India. The highest number of species were recorded from the Andaman and Nicobar islands (588 species) while the smallest number were from Goa and Karnataka state (82 species). The records indicate that the east coast of India, with 803 species, is more diverse than the west coast, which has 446 species.
The taxonomy of the pilumnid crab genus Lophoplax Tesch, 1918, is discussed. Lophoplax sculpta Stimpson, 1858) is redescribed and a neotype is selected in the interests of nomenclatural stability. Two new species allied to L. sculpta are described: L. sordida n. sp. from Indonesia, and L. pannosa n. sp. from Vanuatu. Pilumnus vermiculatus A. Milne-Edwards, 1873, is here transferred to Lophoplax. The poorly known Pseudocryptocoeloma parvus Ward, 1936 (type species of Pseudocryptocoeloma Ward, 1936), known only from Australia thus far, is redescribed and figured; and Pseudocryptocoeloma symmetrinudum Edmondson, 1951 (from Samoa and Japan), is transferred to Lophoplax.
Highly specialized cryptochirid crabs are obligate symbionts of scleractinian corals in tropical and subtropical seas. General morphologies of cryptochirid crabs remain poorly described due to their small size and difficulties in collection; thus, the current inventory is probably an underestimation. In the present study, we sampled cryptochirid crabs from coral communities in Hong Kong. In the literature, only Cryptochirus hongkongensis (now Neotroglocarcinus hongkongensis) with unknown hosts had been recorded in Hong Kong since 1936. In addition to morphological examination, identification in the present study is further supported by sequence divergence of mitochondrial cytochrome c oxidase I (COI) and 16S ribosomal DNA markers. Six operative taxonomic units (OTUs), representing four species and one species complex with two species, were revealed among our material: Cryptochirus coralliodytes, Lithoscaptus paradoxus, Lithoscaptus doughnut sp. nov., Lithoscaptus scottae sp. nov., and Xynomaia sheni species complex. Morphological description of these species is provided, including description of the two new pseudocryptic species. The hosts of the genus Lithoscaptus belong largely to the Merulinidae, while L. doughnut sp. nov. inhabits the Plesiastreidae.
Several intertidal and supratidal systems were investigated in the Brunei Bay to assess the diversity and assemblage structure of grapsoid crabs (Brachyura: Grapsoidea) in different salinity and substrate conditions, type of vegetation, and distance from water bodies. The structure of the assemblages differed remarkably across and within sites, and several taxa were not previously recorded from this region. Diversity decreased towards more terrestrial conditions, with systems closer to the sea supporting more diversified assemblages. High and low intertidal areas also hosted different assemblages in terms of taxonomic composition. Most of these species can be considered habitat specialists, and only occurred in a small number of the investigated areas. A small number of habitat generalists were found in several areas, exhibiting eurytopic ecological traits. A time-based sampling method was used to estimate population densities. A few habitat specialists were recorded in high densities, suggesting adaptations to specific environmental conditions in which these species can bloom. These results highlight how the diversity of these assemblages needs to be considered in management plans, to prevent local extinctions and loss of diversity in the area.
Seven species of calappid crabs were identified from material collected during four IRD-MNHN expeditions conducted in 1998 and 1999 in shallow and deep waters off Fiji. Six species are reported for the first time from the islands. One new species, Mursia murimura n. sp., is described and illustrated. The new species differs from the closely related M. diwata Galil & Takeda, 2004, with which it shares a stout, distally auriculated first male pleopod, by possessing much longer lateral carapacial and cheliped spines.
Brachyuran crabs belonging to the subfamily Ethusinae Guinot, 1977, family Dorippidae MacLeay, 1838, are adapted to carry bivalve shells or other objects on their backs by using the hooked dactyli of their last two pairs of pereopods (P4 and P5), which are dorsally located and mobile. Most species inhabit deep water and are infrequently collected. The taxonomy of the 57 known Indo-West Pacific species of ethusines is revised. The subfamily consists of three genera: Ethusa Roux, 1830, with 30 species of which four are being described as new, Ethusina Smith, 1884, with 25 species of which eight are new, and Parethusa Chen, 1997, with two species of which one is new. Ethusa and Ethusina are worldwide in distribution while Parethusa is exclusive to the Indo-West Pacific region. Seven nominal species described by other authors were found to be junior subjective synonyms of other species: Ethusa major Chen, 1993, of Ethusa orientalis Miers, 1886; Ethusa makasarica Chen, 1993, of Ethusa hirsuta McArdle, 1900; Ethusa madagascariensis Chen, 1987, of Ethusa zurstrasseni Doflein, 1904; Ethusina investigatoris (Alcock, 1896) and E. alcocki Ng & Ho, 2003, of Ethusina robusta Miers, 1886; Ethusina insolita Ng & Ho, 2003, of Ethusina dilobotus Chen, 1993; and Ethusina saltator Ng & Ho, 2000, of Ethusina paralongipes Chen, 1993. © Publications Scientifiques du Muséum national d'Histoire naturelle.
The taxonomy of the gecarcinid land crabs of the genus Discoplax A. Milne Edwards, 1867, is revised, and its differences with the related genus, Cardisoma Latreille, 1828, enumerated. Discoplax had been separated from Cardisoma primarily by its elongated ambulatory legs, but as this is not a reliable generic character, many authors have regarded both names as synonyms. However, a number of new differences (antennal structure, orbits, carapace, thoracic sternal and abdominal characters) show that both are distinct genera. The genus Discoplax now contains four species, the type species D. longipes A. Milne Edwards, 1867, D. hirtipes (Dana, 1852), D. rotunda (Quoy & Gaimard, 1824), and a new species, D. gracilipes, from the Philippines. Discoplax gracilipes is allied to D. longipes but can immediately be distinguished by its relatively longer ambulatory legs and smoother carapace. A key to the known Discoplax species is provided.
Eriphia norfolcensis is separated from Eriphia sensu stricto and placed into a new genus Bountiana. The two genera differ in many features including carapace shape, eye size and shape; differentiation of efferent branchial openings; length of second antennular segment; length and disposition of basal antennal segment; conformation of gonopod 2; and distinctness of suture between male thoracic sternites 2 and 3. A lectotype is designated for E. norfolcensis Grant and McCulloch, 1907.
A new genus and species of portunid crab, Richerellus moosai, is described from five specimens collected in the New Caledonian lagoon, at depths of 15-20 and 50 m. The closest genus to Richerellus is Carupa Dana, 1851, and thus Richerellus is included in the subfamily Carupinae Paulson, 1875. Richerellus differs from Carupa by several characters of which the most remarkable are the number of anterolateral teeth of the carapace and the cheliped length.
The parthenopid crab genus Cryptopodia H. Milne Edwards, 1834, is revised. Cryptopodia H. Milne Edwards, 1834, s. str. is restricted for the Indo-West Pacific taxa, and 12 species are recognised. Two new species, Cryptopodia patula and C. echinosa, are described from India. Cryptopodia laevimana Miers, 1879, is shown to be a valid species. Cryptopodia pentagona Flipse, 1930, and C. sinica Chen & Xu, 1991, are regarded as junior synonyms of C. fornicata (Fabricius, 1781), and C. pan Laurie, 1906, respectively. The two American species, C. concava Stimpson, 1871, and C. hassleri Rathbun, 1925, are redescribed and transferred to a new genus, Celatopesia. Celatopesia is distinguished from Cryptopodia in lacking a dorsal triangular depression and a lateroventral concavity for its legs, having the margins of the antennular fossae granulated, the structure of the shape of the third maxilliped, structures of the fingers and palm of the chelipeds, and male telson shape. Keys to the genera Cryptopodia and Celatopesia as well as their respective species are provided.
The crabs of the genera Ceratocarcinus White, 1847, and Harrovia Adams & White, 1849, are revised. Members of both genera are obligate symbionts of crinoids. Ceratocarcinus White, 1847, now contains three species: C. longimanus White, 1847, C. frontodentata (Shen, Dai & Chen 1982), and C. trilobatus (Sakai, 1938). One species, Ceratocarcinus spinosus Miers, 1879, is referred to a new genus, Tiaramedon. Harrovia is redefined and now contains seven species: H. albolineata Adams & White, 1849, H. cognata, new species, H. elegans De Man, 1887, H. japonica Balss, 1921, A longipes Lanchester, 1900, H. ngi Chen & Xu, 1992, and H. tuberculata Haswell, 1880. Harrovia purpureus Gordon, 1934, and Harrovia egeriae Gordon, 1947, are referred to two new genera, Permanotus and Tauropus respectively.
Majid crabs of the genus Oxypleurodon from Indonesia, New Caledonia and Wallis and Futuna Islands, are studied here and their morphological characteristics precised. The position of this recently rehabilitated genus in relation to the two most closely similar genera Sphenocarcinus A. Milne Edwards, 1878 and Rochinia A. Milne Edwards, 1875, can now be reexamined. Two new species are described, 0. tavaresi sp. nov. from Wallis Is., and 0. karubar sp. nov. from the Moluccas.