TWO NEW SPECIES OF SINGHAPLAX SERÈNE & SOH, 1976 (DECAPODA, BRACHYURA, GONEPLACIDAE) FROM THE PHILIPPINES AND SOLOMON ISLANDS BY TOHRU NARUSE1,3) and PETER CASTRO2,4) 1) Transdisciplinary Research Organization for Subtropical and Island Studies, University of the Ryukyus, 870 Uehara, Taketomi, Okinawa 907-1541, Japan 2) Biological Sciences Department, California State Polytechnic University, Pomona, California 91768-4032, U.S.A. ABSTRACT Two new species of Singhaplax Serène & Soh, 1976, are described based on material from central Philippines and the Solomon Islands. They are superficially similar to congeners as well as species of Microgoneplax Castro, 2007, but can be differentiated from them and each other by their G1 structures. The present study brings the known number of Singhaplax species to 10. A key to the species of Singhaplax is provided. RÉSUMÉ Deux nouvelles espèces de Singhaplax Serène & Soh, 1976, sont décrites à partir de matériel des Philippines centrales et des îles Salomon. Elles sont superficiellement similaires à leurs congénères ainsi qu’aux espèces de Microgoneplax Castro, 2007, mais elles peuvent en être séparées par les structures de leur G1. La présente étude porte le nombre d’espèces de Singhaplax à 10. Une clef des espèces de ce genre est fournie. INTRODUCTION Serène & Soh (1976) established Singhaplax to accommodate Goneplax ockelmanni Serène, 1971 [type species] and G. nipponensis Yokoya, 1933. Castro (2007) redefined Singhaplax and restricted it to G. ockelmanni, with the 3) Corresponding author; e-mail: [email protected] 4) e-mail: [email protected] © Koninklijke Brill NV, Leiden, 2010 Studies on Malacostraca: 535-546 536 CRM 014 – Fransen et al. (eds.), LIPKE BIJDELEY HOLTHUIS MEMORIAL VOLUME addition of Ommatocarcinus orientalis Tesch, 1918, Goneplax wolffi Serène, 1964, Singhaplax dichotoma Castro, 2007, S. platypoda Castro, 2007, S. rhamphe Castro, 2007, and S. styrax Castro, 2007. Subsequently, Takeda & Komatsu (2010) described a new Singhaplax from Japan and Taiwan. Goneplax nipponensis clearly belongs to a different genus, possibly Hadroplax Castro, 2007 (Castro 2007: 722). Singhaplax species are nearly identical to those in Microgoneplax Castro, 2007, in the shape of their carapaces but the male second gonopod of Singhaplax is longer or as long as the male first gonopod whereas that of Microgoneplax is much shorter than the male first gonopod, unlike most goneplacids. Microgoneplax was established for Ommatocarcinus elegans Chen, 1998, and four additional species: M. caenis Castro, 2007 (type species), M. cope Castro, 2007, M. pelecis Castro, 2007, and M. prion Castro, 2007. Recently, two more Microgoneplax species were added (Takeda & Komatsu, 2010; Naruse & Castro, 2010). The present study describes two more species of Singhaplax from the Philippines from the PANGLAO 2004 Expedition (see Bouchet et al., 2009) and Solomon Islands. Specimens examined are deposited in the Muséum national d’Histoire na- turelle, Paris (MNHN); the National Museum of the Philippines, Manila (NMCR); and the Zoological Reference Collection, Raffles Museum of Bio- diversity Research, National University of Singapore (ZRC). Measurements provided are of the carapace length (CL) by the carapace width (CW). The ab- breviations P2-P5, G1 and G2 are used for the second to fifth pereopods, male first and second gonopods, respectively. TAXONOMY Family GONEPLACIDAE MacLeay, 1838 Genus Singhaplax Serène & Soh, 1976 Singhaplax lipkei sp. nov. (figs. 1-3) Material examined. — Holotype, male, 2.7 × 5.6 mm, west of Baclayon, Bohol Island, ◦ ◦ Philippines, PANGLAO 2004, station T6, 34-82 m, 9 35.1 N, 123 51.2 E, 2 June 2004 (NMCR 30097). Paratype, 1 ovigerous female, 3.4 × 6.7 mm, same data as holotype (ZRC 2008.1461). Description. — Carapace (figs. 1, 2a) transversely rectangular, widest be- tween outer orbital angles, CW 1.99-2.07 CL (n = 2), dorsal surface smooth,.