Memoirs of the Queensland Museum | Nature 56 (2) © Queensland Museum 2013 PO Box 3300, South Brisbane 4101, Australia Phone 06 7 3840 7555 Fax 06 7 3846 1226 Email [email protected] Website www.qm.qld.gov.au National Library of Australia card number ISSN 0079-8835 NOTE Papers published in this volume and in all previous volumes of the Memoirs of the Queensland Museum may be reproduced for scientific research, individual study or other educational purposes. Properly acknowledged quotations may be made but queries regarding the republication of any papers should be addressed to the Director. Copies of the journal can be purchased from the Queensland Museum Shop. A Guide to Authors is displayed at the Queensland Museum web site www.qm.qld.gov.au A Queensland Government Project Typeset at the Queensland Museum Revision of the genus Ocypode with the description of a new genus, Hoplocypode (Crustacea: Decapoda: Brachyura) Katsushi SAKAI Shikoku University, Tokushima. Email: [email protected] Michael TÜRKAY Forschungsinstitut Senckenberg, Senckenberganlage 25, D-60325 Frankfurt a. M., Germany Email: [email protected] Citation: Sakai, K. & Türkay, M. 2013 06 30. Revision of the genus Ocypode with the description of a new genus, Hoplocypode (Crustacea: Decapoda: Brachyura). Memoirs of the Queensland Museum — Nature 56(2): 665–793. Brisbane. ISSN 0079–8835. ABSTRACT A taxonomic revision of Ocypode Weber, 1795, has resulted in the recognition of a new genus, Hoplocypode containing a single species H. occidentalis (Stimpson, 1860) that is endemic to the East Pacific. Ocypode is now recognised to contain 21 valid species. Of these, one eastern Pacific, one western Atlantic, and two eastern Atlantic species tend to have widespread distributions within their respective regions. Conversely, many of the 17 Indo-Pacific species exhibit relatively restricted ranges. Only three of them, O. cordimanus, O. ceratophthalma and O. pallidula are widespread. Morphological features and their import- ance in identification are discussed, and a key to all species is provided. q Ocypode, taxonomy, new genus, biogeography, Indian Ocean, Pacific Ocean, Atlantic Ocean. Species in the genus Ocypode are a common descriptions and figures of the male Go1, and and conspicuous feature of tropical and sub- the female genital opening, have been provided tropical sandy beaches worldwide. This is the for the first time for many species, and these reason why specimens have been collected have proved very important in helping to since early times, and there has been so much define species and genera, and in helping to interest in studying them. However, there have understand their phylogenetic relationships. long been problems in identifying some species, and there has been considerable confusion over Abbreviations. c. = ca.; Car = carapace; Go1 = the correct names to use. Some species were Gonopod 1; Mxp3 = Maxilliped 3; P1 = pereio- described from very few specimens and types pod 1; P2–5 = pereiopods 2–5. The measurements have been subsequently lost, some have had of carapace length and width (CL/CW) in the confusion over their original labeling, or were descriptions of the species and the material lists attributed to vague or even wrong localities. are given in mm. AMS = Australian Museum, Thus, the present world revision has, by Sydney; IRSNB = Institut Royal des Sciences necessity, attempted to carefully re-examine all Naturelles de Belgique, Bruxelles; MCM = earlier published specimens, including the types, Museo Civico di Storia Naturale di Milano; as well as the extensive collections of the Sencken - MCG = Museo Civico di Storia Naturale di berg Forschungsinstitut und Naturmuseum in Genova; MZT = Museo e Istituto di Zoologia Frankfurt am Main, and a number of other sistematica dell'Univesitá di Torino; MBL = museums from around the world. We give Museu Bocage Lisboa; MCZ = Museum of complete keys, descriptions, and figures of all Comparative Zoology, Cambridge, Massachusets; the species of the genus known to date to finally MHNG = Museum d'Histoire naturelle, Genève; resolve problems in identification. Detailed MI = Mauritius-Institute, Port Louis, Mauritius; Memoirs of the Queensland Museum — Nature 2013 56(2) www.qm.qld.gov.au 665 Sakai & Türkay MNHN = Muséum national d'Histoire naturelle, usefulness in defining a natural phylogenetic Paris; MW = Museum Wiesbaden, Naturwissen - classification. schaftliche Sammlungen; MZUT = Zoological Stridulating ridge. A stridulating ridge is found Museum of the Turin University; NHM = on the inner surface of the palm of the larger Natural History Museum, London; NHMB = cheliped in all species except for O. cordimanus, Naturhistorisches Museum Basel; NHCY = and its morphology differs among species. It National Natural History Collection Yemen may be composed of tubercles, of tubercles (collection presently at Senckenberg, Frankfurt); with striae, of tubercles and tubercles with NHMW = Naturhistorisches Museum Wien; striae, of tubercles and striae, or solely of striae. NHRS = Naturhistoriska Riksmuseet Stockholm; It is one of the most important characters for QM = Queensland Museum, Brisbane; RMNH distinguishing species, because it can be found = Rijksmuseum van Natuurlijke Historie, even in juveniles. The difference in the Leiden [now ‘Naturalis’]; SMF = Senckenberg structure of the stridulating ridge is closely Museum, Frankfurt am Main; SNMNH = Saudi related to the sound produced for communi- National Museum of Natural History (collection cation, on which interspecific separations are presently at Senckenberg, Frankfurt am Main); based (Popper et al. 2001).We have observed USNM = U.S. National Museum, Washington, that the stridulating ridge is often absent on D.C.; UZMK = Universitetets Zoologiske Museum, regenerated claws (easily recognisable as København; WAM = Western Australian Museum, abnormal because the larger cheliped is similar Perth; ZRCNUS = Zoological Reference Collect - in size to the smaller one). As this would make ions, National University of Singapore; ZSI = sound production impossible, normal communi - Zoological Survey of India, Calcutta; ZSM = cation with other individuals must be severely Zoologische Staatssammlung, München; ZMA impaired. = Zoologisch Museum Universiteit van Amster - As stated, the morphology of the stridulating dam; ZMG = Zoologisches Museum Göttingen ridge is very useful for separating species, (on Permanent loan to Senckenberg); ZMH = however this feature may not be useful in help - Zoologisches Museum Hamburg; ZMK = ing to define relationships between species. Zoologisches Museum Kiel. Selection pressures may actually promote divers- ification between species in order to avoid introgression. Furthermore the detection of TERMINOLOGY plesiomorphies and apomorphies is rendered The terminology we use for the body-parts is difficult, as even species without stridulating based on the thorough descriptions of Balss ridges exhibit a similar mode of sound product - (1940, 1941), and Pesta (1918) and is explained ion (Horch 1975; for Gecarcinus, see Klassen in detail by Sakai et al. (2006). 1973). Von Hagen (1975) postulated that the existence of a stridulating ridge is a synapo- Morphological features and their importance morphy, however the one species lacking this A number of characters can be used for discrim - character, Ocypode cordimanus, stridulates quite inating species within this genus, however efficiently (Horch 1975), so it is difficult to these are not necessarily useful for creating know if the lack of a stridulating ridge in O. natural groupings, and a discussion of their cordimanus is plesiomorphic, or if the ridge has adaptive and phylogenetic value is necessary. been secondarily lost. In Ocypode, classifications simply based on the The suggestion that diversification plays a most obvious morphological characters result major role in determining the morphology, and in different groupings depending on the sound patterns generated, is further supported primary feature used. This was the case in the by the fact that stridulating ridges of sympatric past, and very different and incompatible species are typically very different, while geogra - relationships have been suggested. Therefore, phically distant species can be very similar. For the character complexes used in this paper are example, the stridulating ridge of O. occidentalis here discussed one by one, with regard to their (= H. occidentalis) from the eastern Pacific is 666 Memoirs of the Queensland Museum — Nature 2013 56(2) Revision of Ocypode almost identical with that of O. convexa from 13. Ocypode madagascariensis (Fig. 3D). Stridulating Western Australia, though those two species are ridge composed of 20–30 closely spaced tubercles now classified under different genera according with striae. to the form of Go1. Thus it is apparent that a 14. Ocypode mortoni (Fig. 3E). Stridulating ridge classification based on the shape of the composed of 35–71 striae. stridulating ridge would be artificial. 15. Ocypode nobilii (Fig. 4A). Stridulating ridge The stridulating ridges of Hoplocypode and composed of 99–120 closely spaced fine striae. Ocypode species are characterised as follows: 16. Ocypode pallidula (Fig. 4B). Stridulating ridge 1. Hoplocypode occidentalis (Fig. 1A). Stridulating composed of 30–42 interspaced thick striae. ridge composed of c. 21–22 tubercles. 17. Ocypode pauliani (Fig. 4C). Stridulating ridge 2. Ocypode africana (Fig. 1B). Stridulating ridge composed of 7–13 irregularly