Synalpheus hastilicrassus Coutière, 1905

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 : 381-383

3.2.11 Synalpheus hastilicrassus Coutière, 1905 ( Fig. 17 )

Synalpheus hastilicrassus Coutière, 1905 a . Fauna and Geog. Maid, and Laccad., 2(4): 875, pl. 72, fig. 12; de Man. 1911. Siboga Exped. , 39(2): 263, fig. 45 (parlim); Banner & Banner, 1975. Records of the Australian Museum, 29(12): pl. 353, fig. 21.

Synalpheus hastilicrassus Coutière var.? de Man, 1911. Siboga Exped. , 39(2): 264, fig. 45 (parlim).

Synalpheus hastilicrassus acanthitelsoniformis de Man, 1920 . Zool. Meded., Leiden, 5(3): 108; 1922. Siboga Exped. , 39(5): 29, fig. 14.

Synalpheus acanthitelsonis Coutière, 1905 . Loc. Cit., 2(4): 875, fig. 13; de Man. 1911. Loc. Cit.: 256, fig. 46; Gravely, 1930. Bull. Madras Govt Mus. New Ser. (Nat. Hist.), 1(2): 77, pl. I, fig.1; Banner & Banner, 1966. Siam Soc. Mono., 3: 58, fig. 18.

Material examined. CL 3.2–6.1 mm, TL 6.8–12.1 mm. ( MBM 270350), 1 ovigerous ♀, Tonkin Gulf (Beibu Gulf), Sta. 6167, depth 57 m, 8 October 1960, coll. Bao-Lin Zhang; ( MBM 270351), 1♂, Tonkin Gulf (Beibu Gulf), Sta. 6167, depth 57 m, 8 October 1960, coll. Bao-Lin Zhang; ( MBM 270076), 1 ovigerous ♀, Jinqing Island, Xisha Islands, 23 May 1974; ( MBM 270709), 1 ovigerous ♀, 1♂, Linchang, 3 December 1990; ( MBM 270599), 1 ovigerous ♀, 1♂, Tonkin Gulf (Beibu Gulf), Sta. 7502, depth 32 m, 15 April 1962; ( MBM 270608), 2♂, Tonkin Gulf (Beibu Gulf), Sta. 7305, depth 64m, 18 October 1965; 2 ovigerous ♀, 2♂, depth 9 m, 25 March 1992, coll. Li-Ren Cheng; ( MBM 107764), 2 ovigerous ♀, 3♂, Yalong Bay, Yezhu Island, depth 6–11 m, 20 November 1990; ( MBM 107766), 1♂, Yalong Bay, Yezhu Island, 17 November 1990, coll. Newmann; ( MBM 159244), 1 ovigerous ♀, 1♂, Sanya, dadonghai, depth 7–10 m, 21 November 1997, coll. Xin-Zheng Li; ( MBM 107785), 1♂, Shalao, 4 April 1992; ( MBM 158489), 1 ovigerous ♀; ( MBM 158728), 1♂, Jinqing Island, Xisha Islands, 25 April 1958, coll. Zhen-Gang Fan, Jie-Shan Xu; ( MBM 159299), 3 ovigerous ♀, 4♂; ( MBM 159278), ( MBM 270600), 2♂, 1 ovigerous ♀, Tonkin Gulf (Beibu Gulf), Sta. 7403, depth 38m, 21 August 1962, coll. Fu-Zeng Sun; ( MBM 159310), 3 ovigerous ♀, 2♂, 1 immature specimens, Nanhai, Xincun, depth 1–3 m, 26 March 1992; ( MBM 159279), 4 ovigerous ♀, Yezhu Island, 27 March 1992; ( MBM 158223), 2♂, 26 December 1954, coll. Rui-Yu Liu; ( MBM 159206), 1 ovigerous ♀, Sanya, Dadonghai, depth 5–9 m, 3 December 1997, coll. Xin-Zheng Li; ( MBM 158541), 2 ovigerous ♀, Yalong Bay, Yezhu Island, 19 March 1992, coll. Xin-Zheng Li; ( MBM 158499), 1 ovigerous ♀; ( MBM 158543), 1♂.

Description. Carapace smooth, glabrous; rostrum about 3.2 times as long as wide at base, acute tip overreaching end of first segment of antennular peduncle; orbital hoods shorter than rostrum, longer than wider at base; pterygostomial corner produced into acute angle; cardiac notch well developed.

Telson about 1.2 times as long as wide at base; dorsal surface with two pairs of spines, inserted approximately at 1/3 and 2/3 length of telson; posterior margin strongly produced, fringed with long setae, posterolateral angle each with two pairs of large spines, lateral slightly shorter than mesial, posterolateral margins each produced into large acute tooth, slightly shorter than or subequal to contiguous spines.

Eyes concealed in dorsal and lateral view.

Antennular peduncle moderately slender, with distally acute stylocerite, latter hardly reaching middle of second segment of antennular peduncle; second segment about 1.5 times as long as wide at base; visible part of first segment longer than second and less twice as long as third. Basicerite with or without distodorsal tooth, distolateral tooth variously from distinctly shorter than to subequal to stylocerite; carpocerite far overreaching end of third segment of antennular peduncle; scaphocerite blade moderately narrow, reaching middle of third segment of antennular peduncle, lateral spine developed, overreaching end of antennular peduncle, much shorter than carpocerite.

Third maxilliped far beyond antennular peduncle and carpocerite when extended; antepenultimate segment longest; penultimate segment about 1.5 times as long as wide at base; tip of ultimate segment bearing crown of five long spine-like setae, with transverse rows of setae along ventral margin.

Major cheliped with short, stout ischium; merus about 3 times as long as wide at base, superodistal margin with acute triangular tooth; carpus cup-shaped, with setae distodorsally; palm about 2.3 times as long as dactylus, distodorsal of palm with at most an obtuse projecting; dactylus as long as pollex, distally slightly curved.

Minor chela with merus about 4 times as long as wide at base, superodistal margin with one acute triangular tooth; carpus cup-shaped, proportionally longer that of major cheliped; palm about 1.4 times as long as fingers; dactylus and pollex tapering, superior surface of dactylus bearing row of moderately short setae, extending almost full length of dactylus distal single tooth.

Second pereiopod with ischium shorter than merus; carpus five-segmented, segment ratio subequal to 5: 1: 1: 1: 1.6, with first segment slightly longer than sum of last four segments; dorsal margin of palm convex; fingers about 1.5 times as long as palm. Third pereiopod moderately slender; merus slightly longer than propodus, about 5.3 times as long as wide at base; carpus about 1/3 length of merus, with dorsal margin extended into an obtuse tooth, ventral margin with one distal spine; propodus with 8–9 spines along ventral margin plus one distal pair of spines near dactylus; dactylus about 1/4 length of propodus, slightly curved to propodus, biunguiculate, extensor tooth slightly longer and slightly wider at base than flexor tooth. Fourth pereiopod generally similar to third; ventral margin of propodus with 7 spines plus one distal pair of spines. Fifth pereiopod similar to third and fourth pereiopods, ventral margin of carpus without distal one spine; ventral margin of propodus with 9 transversal rows of spine-like setae and 3 spines.

Remarks. This species is rather complex ( Banner & Banner, 1975). It is readily recognized by the posterior lateral margins of the telson produced into large tooth, slightly shorter than the contiguous spines. The present specimens are generally agreed with the redescriptions ( Banner & Banner, 1975; Chace, 1988), but the distodorsal tooth of the basiceritehas marked variety. This variation lies within that recorded by Banner & Banner.

Distribution. South China Sea; Maldive Archipelago; Gulf of Manaar; Indonesia; Philippiines, Caroline and Marshall Islands; Fiji; Australia.

Figures

Fig. 17. Synalpheus hastilicrassus Coutière, 1905, female (cl 4.1mm) (MBM 159279). a–b. Frontal region. a. Dorsal. b. Lateral. c. Third maxilliped, dorsal. d–e. Major cheliped. d. Mesial. e. Chela, lateral. f–g. Minor cheliped. f. Lateral. g. Chela, lateral. h. Second pereiopod, lateral. i–j. Third pereiopod. i. Lateral. j. Distal propodus and dactylus, lateral. k. Fourth pereiopod, lateral. l. Fifth pereiopod, propodus and dactylus, lateral. m. Second pleopod. n. Telson, dorsal. Scale bars: a–i, k–n=1 mm; j=0.5mm.