Raoulia limosa Ng, 1987

Ng, Peter K. L. & Rahayu, Dwi Listyo, 2014, Revision of the family Acidopsidae Števčić, 2005, and the systematic position of Typhlocarcinodes Alcock, 1900, Caecopilumnus Borradaile, 1902, and Raoulia Ng, 1987, with descriptions of two new genera and five new species (Crustacea: Brachyura: Goneplacoidea), Zootaxa 3773 (1), pp. 1-63 : 23-30

Raoulia limosa Ng, 1987

( Figs. 5C , 13–16 )

Typhlocarcinodes piroculatus — Tesch 1918: 231, pl. 15 fig. 2.— Serène 1964: 237, text-fig. 15, pl. 21A.— Serène 1968: 92 (part). (not Typhlocarcinops piroculata Rathbun, 1911 )

Raoulia limosa Ng 1987: 93 .— Ng et al. 2008: 76.

Material examined. Holotype: male (8.3 × 6.3 mm) ( ZMUC M58 ), off Marongas, Jolo, Philippines , ca. 45 m depth, coll. Th, Mortensen , Pacific Expedition 1913–1916, 20 March 1914. Others — Philippines: 1 male (4.8 × 3.5 mm) ( ZMA 240126 ), station 133, Salibabu I., reef off Lirung, Talaut Is., up to 36 m, coll. SIBOGA Expedition, 25– 27 July 1899; 1 male (5.5 × 4.1 mm) ( ZRC 2013.1708 ), station B12, Panglao I., Doljo Point, 935.6'N 12343.2'E, reef slope, 24–27m, coll. PANGLAO 2004, 14 June 2004; 1 male (4.2 × 3.3 mm) ( ZRC 2013.170 ), station S7, Panglao I., Sungcolan Bay , 938.5'N 12349.2'E, sand with seagrass, 1–4 m, coll. PANGLAO 2004, 9 June 2004; Vietnam: 1 female (6.4 × 4.8 mm) ( ZRC 1970.8.4.15), Nhatrang, coll. R. Serène, 1958. Indonesia: 3 males (7.5 × 5.9 mm, 8.4 × 6.3 mm, 8.3 × 6.5 mm), 4 females (8.1 × 6.1 mm, 7.5 × 5.8 mm, 7.5 × 5.9 mm, 7.6 × 5.8 mm) ( ZRC 2013.1703 ), 3 males (8.6 × 7.2 mm, 8.4 × 6.8 mm, 7.7 × 6.1 mm) ( MZB Cru 3913), Kuta, eastern Lombok , Lesser Sunda Islands, sand with seagrass, 0–3 m, coll. D.L. Rahayu et al., 19 August 2006; 6 males (5.6 × 4.4 mm –6.9 × 5.4 mm), 12 females (4.4 × 3.4 mm – 12.7 × 9.5 mm), 2 ovigerous females (6.4 × 5.0 mm, 7.4 × 5.6 mm) ( ZRC 2013.1704 ), Kecinan, northern Lombok , Lesser Sunda Islands, sand with seagrass, 0–3 m, coll. D.L. Rahayu et al., 3 May 2011; 2 males (8.3 × 6.3 mm, 8.3 × 6.5 mm), 1 female (7.4 × 5.8 mm) ( MZB Cru 3914), Medana, northern Lombok , Lesser Sunda Islands, 0821.791’S 11607.608’E, sand with seagrass, 0–1 m, coll. D.L. Rahayu et al., 12 June 2007; 2 females (7.6 × 5.8 mm, 9.5 × 7.3 mm) ( ZRC 2013.1705 ), Kecinan, western Lombok , Lesser Sunda Islands, 0824.368’S 11603.561’E, sand with seagrass, 0–1 m, coll. D.L. Rahayu et al., 15 May 2007; 2 males (8.6 × 6.7 mm, 7.3 × 5.7 mm), 4 females (8.9 × 7.0 mm, 7.8 × 6.1 mm, 7.1 × 5.6 mm, 6.1 × 4.8 mm) ( QM), Sira, Lombok, coll. D.L. Rahayu et al., 13 June 2007; 3 males (9.0 × 7.0 mm, 6.2 × 4.8 mm, 5.5 × 4.3 mm), 3 females (8.9 × 6.9 mm, 8.1 × 6.3 mm, 8.0 × 6.1 mm) ( ZRC 2013.1706 ), Sira, Lombok, coll. D.L. Rahayu et al., 13 June 2007; 3 males (7.6 × 6.1 mm, 7.2 × 5.9 mm, 6.3 × 5.1 mm), 1 female (6.6 × 5.1 mm) ( NNM), Nara Lombok, coll. D.L. Rahayu et al., 14 June 2007; 2 males (6.4 × 5.0 mm, 8.0 × 6.2 mm) Pulau Buntal, Seram, Moluccas, coll. D.L. Rahayu et al., 29 June 1997 ( ZRC 2013.1707 ).

Diagnosis. Carapace width 1.3 times length ( Figs. 13A , 14A , 15A ). Junction between frontal and supraorbital margins appears right-angled in frontal view ( Figs. 13D , 14C ). Third maxilliped with merus slightly shorter than ischium; ischium width 1.2 times length ( Figs. 5C , 16B ). Ambulatory legs short; length of merus of fourth leg about 3 times maximum width. G1 with distal half distinctly curving laterally outwards in situ, distal part gradually tapering ( Fig. 16D–G ).

Re-description. Carapace subovate, width 1.3 times length; dorsal surfaces mostly smooth, without visible granules, surfaces near margin gently rugose to weakly granulose; regions poorly defined, grooves very shallow, only H-shaped gastric ones just visible ( Figs. 13A , 14A , 15A ). Front entire, with shallow broad median longitudinal depression; slightly produced, bent downwards; margin granular, gently convex to slightly sinuous, lined with numerous long setae that obscures margin ( Figs. 13A , 14A , 15A ). Junction between frontal, supraorbital margins appears right-angled in frontal view ( Figs. 13D , 14C ). Orbit broad, supraorbital margin gently granular, entire ( Figs. 13A, D , 14A, C , 15A ). Anterolateral margins prominently arcuate, subcristate, lined with small granules, without lobes, teeth or celfts; lined with numerous long setae; anterolateral margins gradually confluent with posterolateral margins; posterolateral margins subparallel, anterior part subcristate, granular ( Figs. 13A, D , 14A, C , 15A ). Posterior carapace margin gently concave to sinuous ( Figs. 13A , 14A , 15A ). Suborbital margin entire, granular, without tooth. Suborbital region gently granular ( Figs. 13D , 14C , 16C ). Eyes relatively stout, completely filling orbit, immobile; elongated pear-shaped, tapering to small pigmented cornea ( Figs. 13D , 14C , 16C ). Basal antennal article (article 2) transversely rectangular, lodged in orbital hiatus, distinctly wider than long, medially concave; article 3 quadrate, article 4 distinctly dorsoventrally flattened, twice as long as broad, lateral margins with numerous long plumose setae; flagellum relatively short, entering orbit.

Third maxillipeds relatively short, almost completely covering buccal cavern when closed; palp (dactylus, propodus, carpus) relatively short, tip of dactylus barely reaching distal margin of ischium; merus semicircular, slightly shorter than ischium, surface slightly convex, anterolateral angle gently convex, not produced; ischium quadrangular, 1.2 as long as broad, with very shallow sublateral sulcus; exopod narrow, reaching midpoint of merus, with long flagellum ( Figs. 5C , 13C , 15B, C , 16B ).

Male chelipeds subequal, with long setae lining merus, carpus; merus short; carpus with numerous granules on dorsal surface distally; outer face of palm with rows of small tubercles, approximately arranged longitudinally, or weakly rugose to smooth; fingers shorter than palm; longitudinal ridge on outer surface of dactylus, propodal finger; cutting edges with various sized low teeth ( Figs. 13A, F, G , 14E, F , 15A ).

Ambulatory legs relatively short; third leg longest; dactylus elongated, as long as propodus; long setae on dorsal, ventral margin of all segments, outer surface of dactylus covered with short setae; merus of last ambulatory legs about 3 times as long as broad ( Figs. 13A , 14A , 15A ).

Surface of thoracic sternum generally smooth, parts weakly punctate; sternum relatively wide; st1, 2 completely fused to form triangular plate; st3 separated from st2 by gently concave to almost straight suture; st3, 4 fused with only lateral sutures discernible; st4–8 complete; narrow groove between st7, 8, not reaching distal margin of edge of st7; penis coxal, long, sits on narrow groove between st7, 8, exposed along most of length, st7, 8 appressed on outer part (adjacent to cx5), closing groove, covering penis; male sterno-abdominal cavity relatively deep; press-button mechanism for holding male abdomen present as small rounded tubercle on anterior third of st5 ( Figs. 13C, E , 14B, D , 15B ).

Male abdomen relatively narrow; a1 very broad, medially broad tapering laterally to acutely triangular edge, reaching cx5; a2 rectangular, short, laterally straight; a3–5 fused, only edges of sutures visible; a3 slightly expanded laterally, forming triangular structure; a6 wider than long, rectangular, lateral margins almost straight or slightly concave, slightly shorter than telson; telson triangular with lateral margins gently convex, tip rounded ( Figs. 13B , 14B, D , 16A ).

G1 basally stout, distal half tapering to narrow structure, relatively straight, bent laterally outwards in situ, with scattered large subdistal spinules ( Fig. 16D–G ). G2 longer than G1, slender, sinuous; distal segment elongated, 0.75 length of proximal segment ( Fig. 16H ).

Female chelipeds with outer surface of palm covered by longitudinal rows of small tubercles, those on outer upper margin denser; with short setae on outer surface, upper, lower margins of palm; dactylus with longitudinal ridge medially, scattered tubercles proximally; propodal finger with longitudinal ridge medially; carpus covered by small tubercles, short setae; merus short, with long setae on upper, lower margin, short setae on outer, inner surface. Female abdomen relatively narrow, all somites free; a1 conspicuously broad with sharply tapering acutely triangular lateral margin, reaching cx5 ( Fig. 16I ); vulvae subovate with operculum.

Colour. Fresh specimens collected from Lombok are dirty white overall with pale brown setae.

Remarks. The tuberculation on the chelipeds appears to vary with the size of the specimens. A large male from Lombok (8.3 × 6.5 mm, ZRC 2013.1703) ( Fig. 14E, F ) had a smooth outer surface of the chela, with only weak tuberculation on the proximal part of the palm. Many of the adult males examined have similarly structured chelae. In the similarly sized male holotype (8.3 × 6.3 mm, ZMUC M58) ( Fig. 13F, G ), the outer surface of the palm has distinct tubercles approximately arranged longitudinally, not unlike the condition in females. This may suggest that the chelae in the holotype male may have only recently regenerated.

Distribution. Philippines, Vietnam and Indonesia; intertidal. The specimens from Lombok ( Indonesia) were collected by sieving the sandy mud substrate in seagrass beds.

Figures

FIGURE 5. Right third maxillipeds. A, Acidops cessacii (A. Milne-Edwards, 1878), syntype female (14.1 × 10.0 mm) (NHM 99.3.23.66) Cape Verde (laterally inverted); B, Parapilumnus cristimanus (A. Milne-Edwards, 1873), male (16.3 × 12.5 mm) (ZRC 2003.90), Nansha Is. (Spratly Is.), South China Sea (laterally inverted); C, Raoulia limosa Ng, 1987, holotype male (8.3 × 6.3 mm) (ZMUC M58), off Marongas, Jolo, Philippines; D, Raoulia piroculata (Rathbun, 1911), lectotype female (7.3 × 5.5 mm) (USNM 41359a), Amirante Is., Indian Ocean; E, Raoulia galea sp. nov., holotype male (9.4 × 7.4 mm) (ZRC 2000.0980), Phuket, Thailand; F, Raoulia fortis sp. nov., holotype male (12.0 × 9.2 mm) (MNHN), Santo, Vanuatu (laterally inverted); G, Raoulia calva sp. nov., holotype male (6.6 × 5.2 mm) (ZRC 2013.1721), Society Is., French Polynesia; H, Caecopilumnus hirsutus (Borradaile, 1902), male (7.1 × 5.6 mm) (ZMA 261027), Flores, Indonesia (laterally inverted); I, Caecopilumnus crassipes (Tesch, 1918), male (11.8 × 10.1 mm) (ZRC 2013.1710) Lombok, Indonesia; J, Caecopilumnus loculatus sp. nov., holotype male (8.0 × 6.7 mm) (ZRC 2013.1723), Moorea, French Polynesia (laterally inverted); K, Thecaplax capillosa gen. et. sp. nov., holotype male (11.6 × 9.5 mm) (MZB), Lombok, Indonesia; L, Typhlocarcinodes integrifrons (Miers, 1881), lectotype male (8.5 × 6.9 mm) (NHM 81.24a), Goree I., Senegal.

FIGURE 13. Raoulia limosa Ng, 1987, holotype male (8.3 × 6.3 mm) (ZMUC M58), Jolo, Philippines. A, dorsal view; B, male abdomen; C, anterior thoracic sternum and sterno-abdominal cavity; D, frontal view of carapace; E, posterior thoracic sternum; F, outer view of right chela; G, outer view of left chela.

FIGURE 14. Raoulia limosa Ng, 1987, male (8.3 × 6.5 mm) (ZRC 2013.1703), Lombok, Indonesia. A, dorsal view; B, anterior thoracic sternum and sterno-abdominal cavity; C, frontal view of carapace; D, posterior thoracic sternum; E, outer view of right chela; F, outer view of left chela.

FIGURE 15. Raoulia limosa Ng, 1987, male (4.8 × 3.5 mm) (ZMA 240126), Talaut Is., Philippines. A, dorsal view; B, anterior thoracic sternum and sterno-abdominal cavity.

FIGURE 16. Raoulia limosa Ng, 1987. A–H, holotype male (8.3 × 6.3 mm) (ZMUC M58), Jolo, Philippines; I, female (9.5 × 7.3 mm) (ZRC 2013.1705), Lombok, Indonesia. A, male abdomen; B, left third maxilliped; C, frontal view of carapace showing antennules, antennae, epistome and orbit; D, E, left G1; F, G, distal part of left G1; H, left G2; I, female abdomen. Scales: A–C, I = 1.0 mm; D, E, H = 0.5 mm; F, G = 0.1 mm.