The curious case of "innies": Articles 50.1, 50.1.1 and the citation of authorities in Decapoda Crustacea-a way forward

In the majority of species and genus names in Decapoda Crustacea, the author(s) of the name equate with the author(s) of the work. In a relatively small number of cases, however, the author(s) of the name are either a subset of the authors of the work or are not an author on the work-a phenomenon herein termed "innies". We demonstrate that these two categories should be differentially interpreted according to Articles 50.1 and 50.1.1 of the ICZN Code. To promote stability in cited authorship of historical names, it is proposed that 1) if the author(s) of the name are also an author on the work, these should be universally accepted as "innies", irrespective of any further explanation in the text (including a mere attribution following the taxon name); and 2) that if the author(s) of the name are not an author(s) of the work, these should only be considered as "innies" if a more expansive explanation is given in the text, not merely an attribution of authorship to the taxon name.

Geosesarma sodalis, a new species of vampire crab (Crustacea, Brachyura, Sesarmidae) from a limestone cave in central Sarawak, Malaysia

A new species of semi-terrestrial crab of the genus Geosesarma (Sesarmidae) is described from a limestone cave in central Sarawak, Malaysian Borneo. Geosesarmasodalissp. nov. is characterised by its quadrate carapace, absence of a flagellum on the exopod of the third maxilliped, presence of 10 or 11 sharp tubercles on the dactylus of the chela and a diagnostic male first gonopod structure. This is the sixth species of Geosesarma reported from Sarawak, and the first member of the genus collected from inside caves.

emOvilyra/em, a new genus of leucosiid crab (Crustacea: Decapoda: Brachyura) from the West Pacific

The identities of two species of shallow water Southeast Asian and southern Chinese leucosiid crabs Philyra fuliginosa Targioni-Tozzetti, 1877, and P. olivacea Rathbun, 1909, are clarified; and shown to be synonyms. A new genus, Ovilyra, is established for P. fuliginosa, and it is easily distinguished from Philyra s. str. as well as allied genera by possessing an elongate carapace, a narrow and slender male pleon with somites 1 and 2 articulate, and a male first gonopod which has the distal quarter sharply bent with a well developed subdistal process.

Tritodynamia bengalensis n. sp., a new species of brachyuran crab from West Bengal state, India (Decapoda: Brachyura: Macrophthalmidae)

Tritodynamia bengalensis n. sp. is described on the basis of a male specimen dredged from the shallow coastal waters of West Bengal state, India. The new species is morphologically similar to T. bidentata Yang Tang, 2005 and T. serratipes Anker Ng, 2014, but can be distinguished by the carapace shape, dentition of the pollex, relative length of the dactylus of the third maxilliped, proportions of the propodus of the third pereopod, and structure of the male left gonopod. This is the first record of the genus Tritodynamia from India.

Revision of the freshwater crabs of the Johora tahanensis (Bott, 1966) species group (Crustacea, Brachyura, Potamidae), with a key to the genus

The taxonomy of the potamid freshwater crabs of the Johoratahanensis (Bott, 1966) species group (Potamoidea) is revised. Seven species are recognised, all from Peninsular Malaysia and southern Thailand, three of which are described as new. The three new species were previously identified as J.tahanensis but can be distinguished by characters of the carapace, male first gonopod, and vulva. A revised key to the 18 recognised species of Johora Bott, 1966, is provided.

Revision of the deep-water spider crab genus, Scyramathia A. Milne-Edwards, 1880, with the description of a new species from the Mediterranean and notes on Rochinia A. Milne-Edwards, 1875, and Anamathia Smith, 1885 (Crustacea, Decapoda, Brachyura, Epialtidae)

The taxonomy of the deep-water spider crabs of the genus Scyramathia A. Milne-Edwards, 1880, is revised and four extant species are recognised from the Atlantic and western Indian Ocean: S. carpenteri (Norman, in Thomson 1873) (type species), S. umbonata (Stimpson, 1871), S. hertwigi Doflein, in Chun 1900, and S. tenuipessp. nov.Scyramathia tenuipessp. nov. from the Mediterreanean is easily distinguished from its congeners by its slender and elongate ambulatory legs. All species are diagnosed and figured. The taxonomy of two allied genera from the Atlantic and Mediterranean, Rochinia A. Milne-Edwards, 1875, and Anamathia Smith, 1885, are also treated and their type species redescribed and figured.

On the identity of the poorly known pea crab, Pinnothera obesa Dana, 1852, and description of a new species of Arcotheres Manning, 1993 from the Southwest Pacific (Decapoda: Brachyura: Pinnotheridae)

The pinnotherid crab, Pinnothera obesa Dana, 1852, was originally described on the basis of material from Fiji, but its taxonomic status has long been obscure because the original description and figures are too brief and schematic by modern standards and the types are also lost. Examination of newly collected material from Fiji revealed the presence of two intertidal pinnotherid species assignable to the genus Arcotheres Manning, 1993, one of which is herein identified with Dana's taxon. A neotype is designated for Arcotheres obesus n. comb. in the interest of nomenclatural stability, and a detailed redescription is given. Arcotheres obesus is morphologically similar to A. exiguus (Bürger, 1895) and A. rotundatus (Bürger, 1895), and differentiating characters are discussed. The species is also reported from Peninsular Malaysia. The second species is new to science, here described as Arcotheres ocularius, and is most similar to A. palaensis (Bürger, 1895) and A. arcophilus (Bürger, 1895). The new species is also recorded from Lombok, Indonesia. Arcotheres obesus and A. ocularius n. sp. are associated with bivalve mollusks of the genera Gafrarium spp. (Veneridae) and Anadara spp. (Arcidae), respectively.

Description of the supergiant isopod Bathynomus raksasa sp. nov. (Crustacea, Isopoda, Cirolanidae) from southern Java, the first record of the genus from Indonesia

The giant isopod genus Bathynomus A. Milne-Edwards, 1879, is recorded for the first time in Indonesian waters, from deep waters off southern Java in the Indian Ocean. Bathynomusraksasasp. nov. is described and notes on juvenile specimens of an unidentified species found in the same locality are also provided. Bathynomusraksasasp. nov. is characterized by the large size (averaging at 330 mm), narrowly rounded clypeus apex, prominent longitudinal carina on the clypeus, convex lateral margins of the uropodal exopod and endopod, produced distolateral corners of the uropodal exopod and endopod which have acute ends, an uropodal exopod with a setal fringe of medium length (69%), a pleotelson 1.6 times wider than long with the posterior margin medially concave, and the large number (11–13) of spines on the pleotelson.

New species of pinnotherid crabs from Southeast Asia and Papua New Guinea (Crustacea: Decapoda: Brachyura)

Three new Indo-West Pacific species of pinnotherid crabs are described, one each of Arcotheres, Buergeres and Nepinnotheres. Arcotheres pollus, described from Paway Island, Mergui Archipelago, is most similar to A. boninensis (Stimpson, 1858), A. pernicola (Bürger, 1895) and A. purpureus (Alcock, 1900), sharing a transversely ovate carapace and long, slender, almost styliform dactyli of P4 and 5 that are about twice the length of those of P2 and 3. Buergeres choprai, described from Papua New Guinea, is most similar to B. deccanesis (Chopra, 1931) from eastern India but differentiated by segment proportions and setation of the walking legs. Buergeres tenuipes (Bürger, 1895) is synonymised with B. ortmanni (Bürger, 1895), which is also reported for the first time from Indonesia. A male of an undetermined species of Buergeres from the Philippines, possibly B. ortmanni, is figured and described, documenting the gonopod morphology in Buergeres for the first time. A key to the species of Buergeres based on females is provided. Nepinnotheres fulvia sp. nov. is also described from Papua New Guinea, and resembles N. cardii (Bürger, 1895) from the Philippines and Malaysia but can be distinguished by features of the chelipeds and maxilliped 3.

What is Sesarmops impressus (H. Milne Edwards, 1837) (Crustacea: Brachyura: Sesarmidae)?

The identity of the widely distributed mangrove and riverine sesarmid crab Sesarmops impressus (H. Milne Edwards, 1837) is clarified. The species has been reported from Madagascar to the South Pacific, but its taxonomy was previously confused. On the basis of morphological characters and available molecular evidence (using 16S rDNA and cytochrome oxidase subunit I), Sesarmops impressus is restricted to the western Indian Ocean and S. frontale A. Milne-Edwards, 1869 is confirmed to be its junior synonym. Sesarmops similis (Hess, 1865), long synonymised under S. impressus, is here recognised as a separate species and a neotype from Samoa is designated. The identity of the poorly known S. atrorubens (Hess, 1865), which has often been confused with S. impressus, is also clarified, and a neotype is selected from Fiji. Specimens from the eastern Indian Ocean and western Pacific are here identified as two new species, S. indicus sp. nov. and S. imperator sp. nov.

On the identities of Nepinnotheres vicajii (Chhapgar, 1957) and Arcotheres casta (Antony amp; Kuttyamma, 1971) from western India: conspecificity and taxonomy (Decapoda, Brachyura, Pinnotheridae)

The identity of Nepinnotheres vicajii (Chhapgar, 1957) (described as Pinnotheres vicajii) (Pinnotheridae), a pea crab associated with the bivalve Marcia recens (Holten, 1802), is clarified. On the basis of re-diagnosis of holotype male and freshly collected female specimens from its type locality, P. vicajii is now assigned to Arcotheres Manning, 1993. A second poorly known species from India, Arcotheres casta (Antony Kuttyamma, 1971), originally collected from Meretrix casta (Gmelin, 1791) is also synonymized with A. vicajii.

The Homolidae of the Hawaiian Islands, with notes on the taxonomy of Moloha major (Kubo, 1936) (Crustacea: Decapoda: Brachyura)

Based partly on a collection of homolid crabs captured from baited traps in deep waters off French Frigate Shoals, Northwest Hawaiian Islands, in October 2006, the Hawaiian species of the family Homolidae are reviewed. Known genera and species in the Hawaiian Islands now include two species of Homola (H. orientalis and H. dickinsoni), two species of Lamoha (L. williamsi and L. personata), and five genera that are each represented by a single species (Paramola japonica, Moloha major, Yaldwynopsis hawaiiana, Latreillopsis okala, and Homologenus namakae). Seven of the 14 currently recognized genera of the Homolidae and nine of the 74 known species are now known from Hawaiian waters. Colour notes are included for the first time for two species (H. dickinsoni and Y. hawaiiana). A key to the family Homolidae in Hawaiian waters is included.

Additional notes on the publication of the Narrative, Zoology and Notes from a Journal of Research into the Natural History of the Voyage of H.M.S. Samarang and its consequences for the nomenclature of decapod crustaceans and other taxa

Captain Edward Belcher was instructed by the Lords of the Admiralty to conduct a Surveying Expedition of the various coasts and islands in the Eastern Seas using H.M.S. Samarang. During this voyage from 1843-1846, Assistant-Surgeon Arthur Adams, made a significant contribution to the collection of natural history specimens, and together with fellow officers J. Richards and W. Browne, he prepared numerous drawings used by Belcher to illustrate the Narrative of the voyage. Later, Adams collaborated with Adam White (an Assistant in the Zoological Branch of the British Museum) to describe the Samarang Crustacea, published jointly with Lovell Reeve on the Samarang Mollusca, edited the Zoology of the voyage of H.M.S. Samarang and was the author of Notes from a Journal of the Natural History which was published in the Narrative of the voyage by Belcher. In his Natural History, Adams provided detailed accounts on some of the crustaceans collected with formal descriptions of species new to science thereby making these names available. The history, nomenclature and validity of the crustacean species cited in this work is discussed and a list of the available names is tabulated.

Geosesarmamirum, a new species of semi-terrestrial sesarmid crab (Crustacea, Decapoda, Brachyura) from central Taiwan

A new species of semi-terrestrial sesarmid crab of the genus Geosesarma De Man, 1892, is described from central Taiwan. Geosesarmamirumsp. nov. is distinct in possessing a strong transverse crest on the inner surface of the male chela and a diagnostic male first gonopod which is relatively long and stout, with the distal chitinous part broad and spatuliform. Like most Geosesarma species, G.mirumsp. nov. has large eggs and direct development, contrasting with the only other species known from Taiwan, G.hednon Ng, Liu and Schubart, 2004, which has small eggs and planktotrophic larvae.

Deep-sea spider crabs of the family Epialtidae MacLeay, 1838, from Papuabr />New Guinea, with a redefinition of Tunepugettia Ng, Komai amp; Sato, 2017, and descriptions of two new genera (Crustacea: Decapoda: Brachyura: Majoidea)

The deep-water epialtid spider crab (superfamily Majoidea) material collected from recent French expeditions to Papua New Guinea (BIOPAPUA 2010, PAPUA NIUGINI 2012, MADEEP 2014, and KAVIENG 2014) was studied. In addition to several new records for the country, five new species of Oxypleurodon Miers, 1885, Rochinia A. Milne-Edwards, 1875, and Tunepugettia Ng, Komai Sato, 2017, are described. The taxonomy of Tunepugettia is reappraised, and a new genus, Crocydocinus n. gen., is established, characterised by its smooth ambulatory legs and a distinct male first gonopod structure. Four species from the Bay of Bengal, Sumatra, and Réunion Island, currently placed in Rochinia and Tunepugettia are transferred to Crocydocinus n. gen. and four new species from Papua New Guinea, Philippines, and Vanuatu are described. A new genus, Neophrys n. gen., with one new species from Papua New Guinea, is established, and is characterised by the supraorbital eave being fused with the carapace and the poorly developed pre-orbital angle.

Geosesarma spectrum, a new species of semiterrestrial vampire crab (Crustacea: Decapoda: Brachyura: Sesarmidae) from Brunei Darussalam, Borneo

A new semiterrestrial vampire crab from the family Sesarmidae, Geosesarma spectrum n. sp., is described from Brunei Darussalam (Borneo). The new species is characterised by its colouration in life, relatively large size, and form of the carapace, ambulatory legs and gonopods. The new species is compared to its closest congeners from Borneo. This description brings the number of Geosesarma species to 60.

On a collection of brachyuran crabs from Lakshadweep, Indian Ocean (Crustacea: Decapoda: Brachyura)

The crab fauna (Crustacea: Brachyura) of Lakshadweep (Laccadives), a group of Indian islands in the western Indian Ocean is updated, using material from the intertidal and shallow subtidal areas collected between 2012 and 2015. Fifty-three species were recorded during this study, of which 17 species are newly recorded from the islands, and three are also new records for India. A total of 169 species of brachyuran crabs are now known from Lakshadweep. The taxonomy of Elamena gracilis Borradaile, 1903 (Hymenosomatidae) is clarified and stabilized by the designation of a lectotype.

On the identity of Sundathelphusa philippina (von Martens, 1868) (Decapoda: Brachyura: Gecarcinucidae) from the Philippines, with descriptions of two new species

The taxonomy of the Sundathelphusa philippina (von Martens, 1868) species group (Brachyura; Gecarcinucidae) from the Philippines is revised, and two new species are described. Sundathelphusa philippina sensu stricto is here restricted to the Bicol Peninsula of southern Luzon, and to the islands of Samar and Leyte. It is one of the largest freshwater crabs in the archipelago, reaching carapace widths of more than 53 mm. Sundathelphusa cebu sp. nov. from Cebu Island is superficially similar to S. philippina in morphology but can be separated by a suite of carapace characters. Sundathelphusa quirino sp. nov. from northern Luzon is the most distinct of the three taxa, with a distinctly more swollen carapace, relatively wider male pleon and a straighter male first gonopod. Sundathelphusa spelaeophila Stasolla, Abbarchi Innocenti, 2015, is also shown to be a junior synonym of S. philippina sensu stricto.

Geometric morphometric analysis in female freshwater crabs of Sarawak (Borneo) permits addressing taxonomy-related problems

The taxonomy of freshwater crabs requires a paradigm change in methodological approaches, particularly in investigations that use morphological techniques. The traditional morphometric approach (two-dimensional measurements) tends to be inappropriate for the identification of freshwater crabs due to their variable external morphology and lack of gonopods (conventionally used for the identification of male crabs) in females. In this study, we explore the potential use of the geometric morphometric technique for identification of female freshwater crabs, and identify taxonomic key characteristics of species. The shape of the carapace could be a good characteristic for the identification of female crabs, especially when the geometric morphometric technique is used. It was observed that the shape of the carapace has an advantage over the shape of the pleon and chela because its relatively flat orientation allows more consistent and easier data preparation for geometric morphometric analysis. The geometric morphometric technique is inexpensive, relatively less time consuming to employ, and accurate. This technique is convenient when dissection to examine the gonopods is not possible, which can damage the specimen in the case of endangered or rare species. Since the technique was used herein for only two species, more compelling and extensive evidence is needed before the reliability of the method can be proven.

A collection of crabs (Crustacea, Brachyura) from the southwestern coast of India, with a discussion of the systematic position of Nectopanope Wood-Mason in Wood-Mason & Alcock, 1891 (Euryplacidae)

A report on the brachyuran crabs collected from the southwestern coast of India by the Indian research vessel FORV Sagar Sampada is presented. The material consists of 13 species from three genera and five families, of which four are new records for India: Heteroplaxmaldivensis (Rathbun, 1902) (Euryplacidae), Cryptopodiacollifer Flipse, 1930 (Parthenopidae), Thalamitamacrodonta Borradaile, 1903 (Portunidae), and Paraxanthodescumatodes (MacGilchrist, 1905) (Xanthidae). The cruise also obtained the first known male of Nectopanoperhodobaphes Wood-Mason in Wood-Mason & Alcock, 1891 (type species of Nectopanope Wood-Mason in Wood-Mason & Alcock, 1891), and its characters show that it is in fact a member of the Euryplacidae Stimpson, 1871. The genus had previously been incorrectly classified in the Xanthidae MacLeay, 1838.

Redescription and new records of a poorly known leucosiid crab, Pseudophilyra punctulata Chen Ng, 2003, and description of a new species of Pseudophilyra from Japan (Crustacea: Decapoda: Brachyura)

A poorly known leucosiid crab, Pseudophilyra punctulata Chen Ng, 2003, originally described on the basis of an immature male holotype and an immature female paratype from Singapore, is rediscovered and rediagnosed on the basis of material from Thailand, the Philippines and the Ryukyu Islands (Japan). In addition, a new species closely related to P. punctulata, P. parilis, is described and illustrated on the basis of material from Mie Prefecture, Honshu mainland of Japan. The new species is distinguished from P. punctulata by the coarser granules bordering the lateral carapace margins and the different shape of the gonopods. Pseudophilyra tridentata Miers, 1879, is also compared with P. punctulata and P. parilis n. sp. because of the close similarities in the overall morphology of the carapace and appendages, but can easily be differentiated by the smoother carapace and thoracic sternum surface, different shape of the carapace and the stouter cheliped palm. It is possible that previous records of P. tridentata outside Japan might contain more than one species.

On a new species of freshwater crab, Indochinamonkhinpyae, from northern Myanmar (Crustacea, Brachyura, Potamidae)

A new species of freshwater crab of the genus Indochinamon Yeo & Ng, 2007 (family Potamidae), is described from highlands north of Myitkyina in Kachin State, Myanmar. Indochinamonkhinpyae sp. n. is distinguished from congeners by its very rugose carapace, broad male pleon and distinctively structured male first gonopod; and is the first potamid species recorded from northern Myanmar.

A new species of highland vampire crab (Crustacea: Brachyura: Sesarmidae: Geosesarma) from Serian, Sarawak

A new species of semiterrestrial highland vampire crab of the family Sesarmidae, Geosesarma larsi n. sp., is described from western Sarawak. This brings the number of Bornean Geosesarma species to 12. Geosesarma larsi n. sp. is distinguished from congeners by the structures of the carapace, third maxilliped exopod and gonopods, as well as the proportions of its ambulatory legs. The colour pattern in life is also strikingly different from allied species. Notes on its ecology are provided and conservation threats briefly discussed.

An annotated checklist of the marine brachyuran crabs (Crustacea: Decapoda: Brachyura) of India

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.