Synalpheus coutierei Banner, 1953

Wang, Yan-Rong & Sha, Zhong-Li, 2015, A review of the genus Synalpheus (Crustacea: Decapoda: Caridea: Alpheidae) from China seas, Zoological Systematics 40 (4), pp. 355-435 : 373-376

3.2.7 Synalpheus coutierei Banner, 1953 ( Figs 11–13 )

Synalpheus coutierei Banner, 1953 . Pacif. Sci., 7(1): 36; Banner & Banner. 1966. Siam Soc. Mono., 3: 62, fig. 20; Banner & Banner, 1975. Records of the Australian Museum, 29(12): pl. 343, fig. 18a–i.

Alpheus biunguiculatus de Man, 1888 . Arch. Naturgesch., 53(1): 502, pl. 21, fig. 6; Spence Bate, 1888. Challenger Rept., 24: 562, pl. 101, fig. 4.

Synalpheus biunguiculatus Coutière, 1898 . Bull. Soc. Ent. Fr., 1898 (11): 232, figs 1–4 (Arafura Sea, N. W. Australia); 1905. Fauna and Geog. Maid, and Laccad., 2(4): 873, pl. 71, fig. 8.

Synalpheus biunguiculatus var. exilipes Coutière, 1905 . Fauna and Geog. Maid, and Laccad., 2(4): 874, fig. 10; Balss, 1921. K. Svenska Vetensk. Akad. Handl., 61(10): 9 (Cape Jaubert).

Synalpheus exilipes Johnson, 1962 . Bull. natn . Mus. St. Singapore, 30: 51.

nec. Synalpheus biunguiculatus (Stimpson), 1861 . Proc. Acad. nat . Sci. Philad., 1860: 31: 51.

Material examined. (MBM 158469), 1♂, CL 8.2 mm, TL 21.3 mm; (MBM 157752), 1♂, CL 5.1 mm, TL 12.1mm, 13 May 1958; (MBM 107754), 2♀, 1♂, CL 5.8 mm, TL 15.9 mm, CL 4, 6 mm, TL 12.1 mm, Xisha Islands, 19–21 May 1980, coll. Xiu-Bin Fang; (MBM 107767), 1♀, CL 5.7 mm, TL 15.1 mm, Xisha Islands, 14 April 1975, coll. Xin-Zheng Li; (MBM 158838), 1♀, 1♂, CL 6.0 mm, TL 14.9 mm, CL 5.3 mm, TL 12.8 mm, Xinying, 28 July 1957; (MBM 107763), 1♂, CL 4.7 mm, TL 10.5 mm, Lelong, 25 November 1990; (MBM 107761), 1♂, CL 4.8 mm, TL 10.8 mm, Zhaoshu Island, Xisha Islands, 11 May 1980; (MBM 107771), 1♀, 1♂, CL 8.3 mm, TL 21.1 mm, CL 7.2 mm, TL 16.5 mm, Yalong Bay, Yezhu Island N-coast, depth 8 m, from dead coral, 27 March 1992, coll. Newmann; (MBM158006), 2♀, 1♂, CL 5.7 mm, TL 13.2 mm, CL 4.5 mm, TL 10.3 mm; (MBM 158184), 1♂, CL 5.1 mm, TL 11.3 mm, Yongxing Island, Xisha Islands, 12–13 June 1958.

Description. Carapace smooth, glabrous; rostrum twice as long as wide at base, with lateral margins slightly convex, rounded tip bearing two short setae, reaching 1/2 length of visible part of first segment of antennular peduncle; orbital hoods three times as wide at base as rostrum, subequal to rostrum, with rounded tip bearing two short setae, notches between orbital hoods and rostrum V-shaped; pterygostomial corner produced into blunt acute angle; cardiac notch well developed.

Abdominal somites smooth, glabrous. Telson about 1.3 times as long as wide at base; lateral margin slightly concave posteriorly; dorsal surface with median groove, with two pairs of large spines, inserted approximately at 1/5 and 1/2 length of telson; posterior margin strongly convex, fringed with long setae, posterolateral angle each with two pairs of spines, lateral 1/2 length of mesial, posterolateral corner right angle.

Eyes concealed in lateral and dorsal view.

Antennular peduncle with distally acute stylocerite, latter reaching 1/3–1/2 of second segment of antennular peduncle; second segment 1.5 as long as wide; visible part of first segment longer than second and about twice as long as third. Antenna with basicerite with acute distodorsal tooth, 1/4–1/3 length of distolateral tooth, latter subequal to stylocerite; carpocerite beyond end of antennular peduncle by length of third segment; scaphocerite blade narrow, overreaching second segment of antennular peduncle, lateral spine with lateral margin slightly concave posteriorly, overreaching end of third segment, shorter than carpocerite.

Mouthpart not dissected. Third maxilliped far beyond antennular peduncle and carpocerite when extended; antepenultimate segment longest, about six times as long as wide; penultimate segment about 1.8 times as long as wide at base; tip of ultimate segment bearing crown of 5–6 spine-like setae, with several brush consisting of 6–8 transverse rows of setae along ventral margin.

Major cheliped with short, stout ischium; merus three times as long as wide at base, superodistal margin ending in subacute triangular tooth; carpus cup-shaped, with long setae distodorsally; chela cylindrical, not a bit compressed or twisted, with palm about 2.5 times as long as dactylus, distodorsal tooth palm subacute, slightly upturned; dactylus distinctly longer than pollex.

Minor chela with ventral margin of ischium bearing long setae; merus about 3.5 times as long as wide, longer than that of major cheliped, superodistal margin rounded, without any projecting, ventral margin bearing row of short setae; carpus cup-shaped proportionally longer that of major cheliped; palm about 1.9 times as long as fingers, lateral face near dactylus bearing patch of stiff setae; dactylus tapering, with flexor margin concave, distal single tooth, lateral margin bearing row of long setae; pollex tapering, with flexor surface obliquely convex, distal single tooth, lateral margin bearing row of long setae.

Second pereiopod with ischium distinctly shorter than merus; carpus five-segmented, segment ratio subequal to 4: 1: 1: 1: 2, with first segment shorter than sum of last four segment, segments 2–4 slightly wider than long; fingers 1.5 times as long as palm. Third pereiopod with merus longer than propodus, about four times as long as wide at base, without spines on ventral margin; carpus about 1/3 merus length, with dorsal margin extended into an obtuse tooth, ventral margin with one distal spine; propodus with seven spines along ventral margin plus one distal pair of spines near dactylus; dactylus around 1/6 propodus length, biunguiculate, moderately slender, extensor tooth subequal to flexor tooth; extensor tooth as wide as flexor at base; notch between extensor and flexor tooth U-shaped. Fourth pereiopod generally similar to third; but ventral margin of carpus without distal spine. Propodus of fifth generally similar to that of fourth and third pereiopod, but with six transversal rows of setae along ventral margin plus one pair of spines near dactylus.

Remarks. This species is very similar to S. bispinosus in the combination of characters summarized following: the frontal region of the carapace; the pereiopods; the telson. We agree with the way to distinguish this from S. bispinosus as Banner (1975, pp. 343–346), that the posterolateral margin of sixth pleura of S. bispinosus each with one acute tooth, while S. coutierei without that tooth.

Distribution. South China Sea; From Suez Canal and Persian Gulf south to Mozambique and eastward across the Indo-Pacific.

Figures

Fig. 11. Synalpheus coutierei Banner, 1953, female (cl 8.1 mm) (MBM 158469). a–b. Frontal region. a. Lateral. b. Dorsal. c–d. Major cheliped. c. Mesial. d. Chela, mesial. e–g. Minor cheliped. e. Mesial. f. Merus, mesial. g. Chela, lateral. h. Abdomen. Scale bars=0.5mm.

Fig. 12. Synalpheus coutierei Banner, 1953, female (cl 8.1 mm) (MBM 158469). a. Second pereiopod, lateral. b–c. Third pereiopod. b. Lateral. c. Distal propodus and dactylus, lateral. d–e. Forth pereiopod, lateral. f. Fifth pereiopod, lateral. g–h. Third maxilliped. g. Tip, dorsal. h. Dorsal. i. Telson and uropod, dorsal. Scale bars =0.5 mm.

Fig. 13. Synalpheus coutierei Banner, 1953, male (cl 5.8mm) (MBM 107754). a. Frontal region, dorsal. b. Abdomen. Scale bars= 0.5 mm.