Oxypleurodon Miers, 1885

Yan, Bee, Lee, Forges, Bertrand Richer De & Ng, Peter K. L., 2021, The generic affinities of the Indo-West Pacific species assigned to Rochinia A. Milne-Edwards, 1875 (Crustacea: Brachyura: Majoidea: Epialtidae), Raffles Bulletin of Zoology 69, pp. 19-44 : 28

Oxypleurodon Miers, 1885

Oxypleurodon Miers, 1885: 588 . – Miers, 1886: 38. – Tavares, 1991: 167, 169. – Ng et al., 2008: 104. – Richer de Forges & Ng, 2009a: 2 . – Richer de Forges & Ng, 2009b: 250 . – Richer de Forges, 2010: 646.

Nasutocarcinus Tavares, 1991: 160 (list), 169. – Ng et al., 2008: 104.

(For a complete synonymy of the genus, see Richer de Forges, 2010: 646).

Type species. Oxypleurodon stimpsoni Miers, 1885 , by monotypy.

Species composition. With 34 species ( Table 1).

Comparative material examined. See Appendix 1.

Diagnosis. Carapace pyriform, with strongly projecting lateral branchial spines or plates. Pseudorostral spines short to long, slender, slightly diverging at approximately 30° angle or less, sometimes subparallel or fused along most of length. Supraorbital eave forms plate with distinct preorbital angle; postorbital lobe fused with hepatic angle forming L-shaped lobe, with some species not fused with postorbital lobe cup-like, blunt anterior margin ( Richer de Forges & Ng, 2009b: figs. 2C, D, 3A–F, 4A, C, 6A, 7A–F; Fig. 6A ). Carapace usually with distinct plates on each region ( Richer de Forges & Ng, 2009b: figs. 2C, D, 3A–F, 4A, C, 6A, 7A–F; Fig. 6A ). Antennal flagellum shorter than to longer than pseudorostral spines ( Richer de Forges & Ng, 2009b: figs. 4B, D, 6B; Fig. 6B ). Basal antennal article longer than broad, with outer margin relatively straight. Distal angle of buccal frame blunt, not raised. Pterygostomial region with single raised plates or granules on outer margin ( Richer de Forges & Ng, 2009b: figs. 4B, D, 6B; Fig. 6B ). Chelipeds stout; propodus slightly inflated with outer margin carinate; carpus with carinate outer margin; merus triangular in cross-section with carinate margins. Ambulatory legs slender, articles with carinate margins or rounded margins; merus with blunt distal angle; P2 longest ( Fig. 6A ). Male thoracic sternum concave anteriorly; sternites 3, 4 narrow, lateral margins constricted. Male pleon triangular, telson triangular; surface of somites smooth ( Richer de Forges & Ng, 2009b: fig. 4B, D; Fig. 6B ). G1 straight, with distal tip sharp ( Richer de Forges & Ng, 2009b: figs. 10A–F, 11A–F; Fig. 9C, D ); G2 slight curve, distal outer margin concave, distal tip rounded ( Richer de Forges & Ng, 2009b: fig. 11G, H).

Remarks. Oxypleurodon was considered to be a junior synonym of Rochinia A. Milne-Edwards, 1875 , by Griffin & Tranter (1986a), but was later resurrected by Tavares (1991) (see also Richer de Forges & Ng, 2009b; Lee et al., 2015). Nasutocarcinus Tavares, 1991 , however, was synonymised with Oxypleurodon by Richer de Forges (2010). There have been a number of changes to the generic boundaries between Oxypleurodon Miers, 1885 , Sphenocarcinus A. Milne-Edwards, 1875 , and Rochinia A. Milne-Edwards, 1875 ( Richer de Forges & Ng, 2009b; Lee et al., 2015). Oxypleurodon was revised by Richer de Forges & Ng (2009b) and they also redefined Sphenocarcinus A. Milne- Edwards, 1875, for its type species, S. corrosus A. Milne- Edwards, 1875. Richer de Forges & Ng (2009b) established Rhinocarcinus for R. agassizi Rathbun, 1893 . With the present inclusion of O. fultoni ( Grant, 1905) , there are now 34 species in Oxypleurodon (see also Richer de Forges & Ng, 2009a, b; Richer de Forges, 2010; Richer de Forges & Corbari, 2012; Lee et al., 2015; Lee et al., 2017; Lee et al., 2019) ( Table 1).

Figures

Fig. 6. A–C, Oxypleurodon fultoni (Grant, 1905) new combination, holotype male (8.2 × 5.1 mm) (AM G.5427), Australia; D–F, Pugettia vesicularis (Rathbun, 1907) new combination, holotype male (14.6 × 10.6 mm) (USNM32860), Galapagos. A, D, overall dorsal view; B, E, overall ventral view; C, F, lateral view of carapace.

Fig. 9. Left G1 and G2. A, B, Laubierinia globulifera (Wood-Mason, in Wood-Mason & Alcock, 1891) new combination, male (9.2 × 6.0 mm) (AM P.34652), Indonesia; C, D, Oxypleurodon fultoni (Grant, 1905) new combination, holotype male (8.2 × 5.1 mm) (AM G.5427), Australia; E, F, Pugettia vesicularis (Rathbun, 1907) new combination, holotype male (14.6 × 10.6 mm) (USNM32860), Galapagos; G–J, Siderochinia kagoshimensis (Rathbun, 1932) new combination, holotype male (11.2 × 6.8 mm) (USNM 48253), Japan (after Lee et al., 2017: fig. 11E, F); K, L, S. aglaos, new species, holotype male (10.7 × 6.9 mm) (ZRC 2016.0549), South China Sea (after Lee et al., 2017: fig. 11G–J). A, C, E, G, K, ventral view; B, D, F, H, L, dorsal view; I, ventral view of G2; J, dorsal view of G2. Scale bar = 1 mm.