Upogebia darwinii ( Miers, 1884 )

Dworschak, Peter C. & Anker, Arthur, 2022, Axiidea (Crustacea: Callianassidae, Callichiridae and Ctenochelidae) and Gebiidea (Upogebiidae) collected during the Comprehensive Marine Biodiversity Survey of Singapore, Raffles Bulletin of Zoology 70, pp. 108-133 : 117-119

Upogebia darwinii ( Miers, 1884)

( Figs. 2c, d , 8)

Gebiopsis Darwinii Miers, 1884: 281 , pl. 32, fig. 3.

Upogebia darwini . — Ngoc-Ho, 1977: 439 (part), figs. 1–3; — 1979: 155.

Upogebia (Upogebia) darwini . — Sakai, 1982: 17, figs. 3a, 4a–c, pls. A1–3, C3.

Upogebia darwinii . — Sakai, 2006: 101 (part), fig. 15; — NgocHo, 2008: 150, fig. 10.

Not Upogebia (Calliadne) Darwinii. — de Man, 1928: 84 (part), pl. 8, figs. 12, 12a, b; pl. 9, fig. 12c–f [= U. intermedia (de Man, 1888) ].

Not Upogebia darwini . — Ngoc-Ho, 1977: 439 (part), fig. 4a–e [= U. carinicauda ( Stimpson (1860)], fig. 4f–h [= U. barbata ( Strahl, 1862) ].

Not Upogebia (Calliadne) darwinii. — Poore & Griffin, 1979 (part): 292, fig. 46 [= Upogebia carinicauda ( Stimpson, 1860) ].

Not Upogebia darwinii . — Sakai, 2006: 101 (part), figs. 14A, B, 16 [= U. hexaceras ( Ortmann, 1894) ].

CMBS material. 1 male (43/12.7) ( ZRC 2018.0561 ), 1 ov. female (47/13.4), 1 male (23/7.0) ( ZRC 2018.0562 ), sta. DR246, north-west of Pulau Sudong, MPA grid 4213, sand, small rocks, rectangular dredge, 22.0– 25.2 m, coll . TMSI team, 12 December 2013 (SEA-2684, 2581); 1 male (40/12.0) ( NHMW 26037 ), ov. female (44/12.6) ( NHMW 26038 ), sta. TB069, Straits of Singapore near Pulau Sudong and Pulau Semakau , 1°13.155′N 103°43.880′E, sandy bottom, beam trawl 17.9–18.9 m, coll. B Richer de Forges et al., 26 May 2013 (SS-1654); 1 male (46/13.1) ( NHMW 26039 ), 1 ov. female (35/10.1) ( NHMW 26040 ), sta. TB072, Straits of Singapore, 1°13.227′N 103°45.313′E, mud, sand, beam trawl, from Xestospongia testudinarium , 23.1–23.6 m, coll. B Richer de Forges et al., 26 May 2013 (SS-0384); 1 male (39/11.1) ( ZRC 2018.0550 ), sta. TB187, Straits of Singapore near Raffles Lighthouse, 1°09.239′N 103°44.674′E, sponges, rocks, gravel, beam trawl 39.5–40.2 m, coll. B Richer de Forges et al., 6 June 2013; 1 ov. female (44/12.4) ( ZRC 2018.0529 ), sta. TB73, Straits of Singapore south of Pulau Semakau , 1°11.282′N 103°46.6321′E, sandy bottom, beam trawl 24.6–29.8 m, coll. B Richer de Forges et al., 26 May 2013 (SS-0385); 1 ov. female (30/8.6) ( ZRC 2018.0535 ), 1 male (31/8.7) ( ZRC 2018.0536 ), sta. DW027, Pulau Ubin, off eastern coast of Chek Jawa, 1°24.927′– 1°25.273′N 103°59.980′– 103°59.692′E, mud, window pane shells, beam trawl 9.9–19.1 m, coll. B Richer de Forges et al., 19 October 2012 (JS-1385) .

Diagnosis. Lateral ridges of gastric region projecting forward. Linea thalassinica not reaching posterior end of carapace. Rostrum longer than eyestalks, with 4 frontal teeth. Ocular spine absent. Antennal peduncle longer than antennular peduncle. First pereopod chelate; ischium with few lower spinules; merus with small lower spines, without proximal upper spine; carpus with moderate upper spine, but without median and lower spines; propodus smooth on lower mesial face and upper border; dactylus with row of tubercles on mesial face and prominent rounded tooth proximally; fixed finger with serrated cutting edge. Second pereopod merus without proximal upper spine; propodus 2.1–2.5 times as long as high. Third pereopod merus with smooth lower border, without proximal upper spine. Pleomere 6 without lateral spines; posterior border minutely tuberculated. Uropodal endopod triangular. Telson 0.8–1.0 as long as maximal width; inverted U-shaped carina with tubercles. Third maxilliped exopod flagellate, no epipods on first and third maxilliped. Arthrobranchs of type A. Embryos 570–860 µm in diameter.

Distribution. Distributed in the Indo-Pacific, from the Red Sea to northern Australia ( Sakai, 2006).

Habitat. In sand, silt, coral rubble, gravel, from the intertidal zone to 50 m; often found in sponges ( Dworschak, 2000; Sepahvand et al., 2013; this study); occasionally boring in corals ( Scoffin & Bradshaw, 2000).

Remarks. The syntype series of U. darwinii consists of 3 males and 3 females from Darwin, Australia (NHMUK 1882:7) and a male-female pair from Singapore (NHMUK 1882:24) ( Ngoc-Ho, 1977). A male from Darwin with TL 20 mm was selected by Sakai (1982: 20) as lectotype, while he excluded the specimens from Singapore from the type series and attributed them to U. ancylodactyla de Man, 1905 (see below). Later, Sakai (2006: 94, 101, 113) attributed the Singaporean material to U. barbata , listing the specimens figured by Ngoc-Ho (1977) partly under U. darwinii ( Sakai, 2006: 94) and as a synonym of U. ancylodactyla ( Sakai, 2006: 91) . It seems that the current taxonomic confusion of this species complex can only be solved by a more comprehensive revision, integrating both morphology and DNA.

Figures

Fig. 2. Specimens, habitus (dorsal and ventral views), showing colouration in life: a, Upogebia carinicauda (Stimpson, 1860), male (21/6.1) (NHMW 26035); b, same, male (23/6.6) (NHMW 26034); c, d, U. darwinii (Miers, 1884), ovigerous female (44/12.6) (NHMW 26038); e, U. hexaceras (Ortmann, 1894), male (23/7.0) (ZRC 2018.0557); f, same, ovigerous female (22/6.1) (NHMW 26042); g, U. ancylodactyla de Man, 1905, female (40/11.3) (ZRC 2018.0551); h, same, male (29/8.4) (ZRC 2018.0549). Not to scale. [Photographs by AA].