Synalpheus tumidomanus

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. 357-435 : 428-434

Synalpheus tumidomanus ( Paul’son, 1875)

( Figs 48–51 )

Alph.[eus] tumido-manus Paul’son, 1875. Studies Crustacea Red Sea, Part I: 101, plate 13, figs 2–2i.

Alph.[eus] tumido-manus var. Alph.[eus] gracili-manus Paul’son, 1875. Studies Crustacea Red Sea, Part I: 102, plate 13, figs 3–3c. Synalpheus Hululensis Coutière, 1908 . Bull. Soc. philomath. Paris IX, 11(5): 202.

Synalpheus Mac-Cullochi Coutière, 1908 . Bull. Soc. philomath. Paris IX, 11(5): 203.

Synalpheus tumidomanus var. exilimanus Coutière, 1909 . Proc, U. S. natn. Mus. 36(1659): 10.

Synalpheus Theophane de Man, 1910 . Tijdschr. ned. dierk. Vereen, 11(4): 292.

Synalpheus anisocheir Stebbing, 1915 . Annals of the South African Museum. 86, plate 87.

Synalpheus japonicus Yokoya, 1936 . Japanese Journal of Zoology 7: 129–146,133, fig. 3.

Material examined. CL 4.2–6.1 mm, TL 7.5–13.9 mm. (MBM 159000), 3 ovigerous ♀, Sanya, Dadonghai, depth 2–3 m, 5 March 1997, coll. Xin-Zheng Li; (MBM 158898), 2♂, Sanya, Donghai, depth 2–3 m, 5 March 1997, coll. Xin-Zheng Li; (MBM 159158), 1 ovigerous ♀, 1♂, Sanya, Dadonghai, depth 6–9 m, 2 December 1997; (MBM 159310), 1 non-ovigerous ♀, Xincun, depth 1–3 m, 26 March 1992; (MBM 158202), 1♂, Sanya, Dadonghai, 1 March 1997, coll. Xin-Zheng Li; (MBM 159160), 1♂, Sanya, Dadonghai, 17 November 1997, coll. Xin-Zheng Li; (MBM 270055), 2 ovigerous ♀, 2♂, Xizhou island, 30 December 1955; (MBM 157827), 2 ovigerous ♀, 1♂, Shalao, depth 6 m, 4 April 1992; (MBM 158171), 1♂, Sanya, Dadonghai, 1 March 1997, coll. Xin-Zheng Li; 1♂, Xincun, 22 December 2007, coll. Lan-Ping Ding, Yong-Qiang Wang; (MBM 158503), 1♂, Yezhu Island, depth 10 m, 18 March 1992; (MBM 158887), 1 ovigerous ♀, Sanya, Dadonghai, 1 March 1997, coll. Xin-Zheng Li; (MBM 158724), 2 ovigerous ♀, 1♂, Shalao, depth

2 m, 4 April 1992; (MBM 107824), 10 ovigerous ♀, 4♂, Shalao, 5 April 1992; (MBM 107778), 1 ovigerous ♀, 2♂, Shalao, depth 6 m, coll. Xin-Zheng Li; (MBM 107745), 1♂, Shalao, 7 November 1990; (MBM 159158), 1 ovigerous ♀, 1♂, Sanya, depth 6–9 m, 2 December 1997; (MBM 156160), 1 ovigerous ♀, Sanya, Dadonghai, 17 November 1997, coll. Xin-Zheng Li; (MBM 107784), 3 ovigerous ♀, Shalao, depth; 12 m, 4 April 1992; (MBM 159299), 2 ovigerous ♀, 1♂; (MBM 107824), 2 ovigerous ♀, 1♂, Shalao, 5 April 1992; 1 ovigerous ♀, 2♂, Subi Reef, Nansha Islands, depth 3 m, 8 May 2004, coll. Yong-Qiang Wang; 1 ovigerous ♀, 1♂, Subi Reef, Nansha Islands, depth 2 m, 8 May 2004; (MBM 270163), 1♂, Tonkin Gulf (Beibu Gulf), Sta. 6210, depth 37 m, 8 January 1959, coll. Zhen-Gang Fan; (MBM 159244) 1♂; (MBM 158071), 1 non-ovigerous ♀, Dengqing island, 3 May 1958, coll. Zhen-Gang Fan, Jie-Shan Xu; (MBM 159262), 3♂, Sanya, Dadonghai, depth 4–6 m, 1 December 1997.

Description. Carapace smooth, glabrous; rostrum about twice as long as wide at base, acute tip not reaching or slightly 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 1.3 times as long as wide at base; dorsal surface with two pairs of spines, inserted approximately at 2/5 and 3/4 length of telson; posterior margin strongly produced, fringed with long setae, posterolateral angle each with two pairs of spines, lateral about 1/3 length of mesial, posterolateral margins each produced into acute tooth, but distinctly shorter than contiguous short spines.

Eyes concealed in dorsal and lateral view.

Antennular peduncle moderately slender, with distally acute stylocerite, latter 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 shorter than stylocerite; carpocerite overreaching end of third segment of antennular peduncle; scaphocerite blade moderately narrow, reaching end of third segment of antennular peduncle, lateral spine developed, overreaching end of antennular peduncle, subequal to or longer 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 one acute triangular tooth; carpus cup-shaped, with setae distodorsally; distodorsal of palm with at most an obtuse projecting or strongly acute tooth, slightly curved to dactylus; dactylus slightly longer than pollex, distally slightly curved.

Minor chela with merus about 3.6 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 1.3 times as long as fingers; dactylus and pollex tapering, distal single tooth.

Second pereiopod with ischium shorter than merus; carpus five-segmented, first segment subequal to sum of last four segments; dorsal margin of palm convex; fingers near as long as palm. Third pereiopod moderately stout; merus slightly longer than propodus, about 4 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 6–8 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 than flexor tooth, notch between extensor and flexor tooth V-shaped, flexor tooth wider at base than or sub-wider at base to extensor tooth. Fourth pereiopod generally similar to third; ventral margin of propodus with 5–7 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 5–8 transversal rows of spine-like setae and 3–5 spines.

Remarks. This species is rather complex ( Banner & Banner, 1968, 1975). The present specimens are mainly variable in the following characters: the length of the rostrum; the present or absent distodorsal tooth of the basicerite; the superior distal margin projecting of the palm in the major chela; the relative wide at base of the extensor and flexor tooth of the third pereiopod.

Distribution. South China Sea; Mediterranean coast of Israel and Red Sea to South Africa, eastward to Japan;

Philippines; Indonesia; Australia and across the Pacific to the Phoenix Islands.

Key of the genus Synalpheus from China seas (modified from Banner & Banner, 1975; Chace, 1988)

1.

2.

3.

4.

5.

6. Without orbitorostral process ............................................................................................................................................................... 2 With orbitorostral process ....................................................................................................................................................................6 Rostrum overreaching end of first segment of antennular peduncle and much longer than orbital hoods; dactylus of minor chela tapering ................................................................................................................................................................................................3 Rostrum much shorter than end of first segment of antennular peduncle and subequal to orbital hoods; dactylus of minor chela spatulate ...............................................................................................................................................................................................5 Distodorsal of palm of major chela without any projecting; distal of merus of third pereiopods normal, without acute tooth ..............

.......................................................................................................................................................................................... S. carinatus Distodorsal of palm of major chela with one subacute projecting; distal of merus of third pereiopods bearing an acute tooth ...........4 Stylocerite reaching to about midlength of first segment of antennular peduncle....................................................... S. odontophorus Stylocerite reaching or overreaching end of first segment of antennular peduncle ........................................................... S. stimpsonii Merus of major and minor chela with superodistal margin rounded, without any projecting ..................................... S. pescadorensis Merus of major and minor chela with superodistal margin with acute triangular tooth .................................................. S. liui sp. nov. Dactylus of third pereiopods triunguiculate, but with inferior unguis at times reduced to a subacute angle ........................................7

Dactylus of third pereiopods biunguiculate, never more than slight swelling as indication of third unguis.......................................10

7. Posterior margin of sixth abdominal somite projecting as 7–10 small teeth .................................................................... S. mortenseni Posterior margin of sixth abdominal not projecting as teeth ................................................................................................................8

8. Spines on propodus of third pereiopods confined to distal quarter or less; dorsal spines of telson either greatly reduces or absent...... .............................................................................................................................................................................................. S. demani Spines on propodus of third pereiopod with spines along entire length; dorsal spines of telson always present and conspicuous ...... 9

9. Merus of third pereiopod with spines on ventral margin................................................................................................. S. nilandensis Merus of third pereiopod without spines on ventral margin..................................................................................................... S. fossor

10. Sixth abdominal somite with acute posterior projection either side of base of telson ........................................................................ 11 Sixth abdominal somite without posterior projection either side of base of telson ............................................................................ 12

11. Rostrum much longer than orbital teeth, distolateral tooth of basicerite much shorter than stylocerite ........................... S. trispinosus Rostrum subequal to orbital teeth, distolateral tooth of basicerite subequal to stylocerite ................................................ S. bispinosus

12. Distal of dactylus and pollex of minor chela with 3 or 2 teeth ......................................................................... S. jinqingensis sp. nov. Distal of dactylus and pollex of minor chela tapering, single tooth ................................................................................................... 13

13. Basicerite usually without distodorsal tooth....................................................................................................................................... 14 Basicerite with distodorsal tooth ........................................................................................................................................................23

14. Dactylus of minor chela with definite longitudinal row of setae on crest or inner face...................................................................... 15 Dactylus of minor chela bearing setae, but not in rows or patches..................................................................................................... 16

15. Stylocerite shorter than first segment antennular peduncle, and short than distolateral tooth of basicerite; raw of setae on dactylus of minor chela medial to crest of finger; outer angles of telson small ............................................................................. S. lophodactylus Stylocerite overreaching end of first segment antennular peduncle, and subequal or longer than distolateral tooth of basicerite; row of setae on dactylus of minor chela on crest of finger; outer angles of telson usually heavy and strongly projecting............................ .................................................................................................................................................................................... S. hastilicrassus

16. Telson with posterior angles rectangular ............................................................................................................................................17 Telson with posterior angles usually acutely produced ......................................................................................................................21

17. Distolateral tooth of basicerite much longer than stylocerite ............................................................................................................. 18 Distolateral tooth of basicerite shorter than stylocerite ...................................................................................................................... 20

18. Posterior margin of telson strongly protruding.................................................................................................. S. tonkinensis sp. nov. Posterior margin of telson almost straight.......................................................................................................................................... 19

19. Tip of third maxilliped bearing only fine setae ....................................................................................................................... S. theano Tip of third maxilliped bearing circlet of short heavy spines .............................................................................................. S. neptunus

20. Third pereiopods slender, with extensor tooth of dactylus longer and wider at base than flexor tooth ..................... S. biunguiculatus Third pereiopods stout, with extensor tooth of dactylus subequal to and much narrower at base than flexor tooth............... S. charon

21. Rostrum long and slender, overreaching middle of second segment of antennular peduncle, 5 or more times as long as wide at base. ..................................................................................................................................................................................... S. gracilirostris Rostrum shorter and more triangular, hardly overreaching end of first segment of antennular peduncle, not more than 3 times as long as wide at base ........................................................................................................................................................................... 22

22. Dactylus of third pereiopods with uniform taper, and with extensor tooth longer and often wider at base than flexor tooth................. ................................................................................................................................................................................... S. tumidomanus Dactylus of third pereiopods with slight swelling on inferior surface proximal to flexor tooth, flexor tooth subequal to or slightly shorter than and wider at base than extensor tooth...................................................................................................... S. paraneomeris

23. Merus of third pereiopods unarmed with spines ................................................................................................................................ 24 Merus of third pereiopods armed with spines ....................................................................................................................................25

24. Rostrum distinctly shorter than orbital tooth; scaphocerite blade and lateral spine much reduced; posterior pair of spines inserted posterior on dorsal margin of telson................................................................................................................... S. brevrostrus sp. nov. Rostrum subequal to orbital teeth; scaphocerite blade and lateral spine normal developed; posterior pair of spines inserted middle on dorsal margin of telson.................................................................................................................................................... S. coutierei

25. Superior distal margin of palm of major chela with two conical, obtuse tubercles, directed forward and upturned .............................. .................................................................................................................................................................................. S. bituberculatus Superior distal margin of palm of major chela with an acute tooth, straight or proximal to dactylus ................................................ 26

26. Extensor tooth of dactylus of third pereiopods less than half as long and less than half as wide at base as flexor tooth ................... 27 Extensor tooth of dactylus of third pereiopods subequal to or slightly shorter than and about half as wide at base as flexor tooth....... ..........................................................................................................................................................................................................28

27. Fingers of minor chela compressed and subequal to or slightly shorter than palm ............................................................. S. neomeris Fingers of minor chela not compressed and about half length of palm ................................................................................. S. iphinoe

28. Rostrum slender, about 5 times as long as wide at base, reaching middle of second segment of antennular peduncle ....... S. modestus Rostrum shorter, less than 3 times as long as wide at base, hardly reaching end of first segment of antennular peduncle ................29

29. Third pereiopod with terminal teeth of dactylus longer, 1/4–1/3 as long as segment................................................ S. streptodactylus Third pereiopod with terminal teeth of dactylus much reduced, 1/10–1/6 as long as segment........................................................... 30

30. Propodus third pereiopod with distinct superior curvature, ventral margin with only two spines, plus one or two terminal spines ...... ............................................................................................................................................................................................. S. pococki Propodus of third pereiopod only slightly curved, ventral margin with numerous spines...................................................... S. iocasta

Funding This work was supported by the National Natural Science Foundation of China (31172054) and partly supported by the project of the S & T basic work from the Ministry of Science and Technology of China (2014FY110500, 2015FY 210300).

Acknowledgements We are much indebted to the late Prof. Rui-Yu Liu (Institute of Oceanology, Chinese Academy of Sciences) for support of the work.

Figures

Fig. 48. Synalpheus tumidomanus (Paul’son, 1875), female (MBM 159000). a–b. Frontal region. a. Dorsal. b. Lateral. c. Third maxilliped, dorsal. d–e. Major cheliped. d. Lateral. e. Chela, lateral. f–g. Minor chela. f. Merus, 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, ventral. m. Second pleopod. n. Telson, dorsal. Scale bars: a–i, k, m–n=1 mm; j, l=0.5 mm.

Fig. 49. Synalpheus tumidomanus (Paul’son, 1875), male (MBM 159158). a–b. Frontal region. a. Dorsal. b. Lateral. c. Third maxilliped, ventral. d–e. Major cheliped. d. Lateral. e. Chela, lateral. f–g. Minor chela. f. Merus, lateral. g. Chela, lateral. h. Minor chela, merus, lateral. i. Second pereiopod, lateral. j–k. Third pereiopod. j. Lateral. k. Distal propodus and dactylus, lateral. l. Fourth pereiopod, lateral. m. Fifth pereiopod, propodus and dactylus, ventral. n. First pleopod. o. Second pleopod. p. Abdomen. q. Telson, dorsal. Scale bars: a–f, h–i, k, o–p=1 mm. g, j, l–n =0.5 mm.

Fig. 50. Synalpheus tumidomanus (Paul’son, 1875), male (MBM 159244). a–b. Frontal region. a. Dorsal. b. Lateral. c. Third maxilliped, dorsal. d–e. Major cheliped. d. Lateral. e. Chela, lateral. f–g. Minor chela. 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, ventral. m. Abdomen. n. Telson, dorsal. o. Second pleopod. Scale bars: a–i, k, m–n = 1 mm; j, l, o=0.5mm.

Fig. 51. Synalpheus tumidomanus (Paul’son, 1875), male (MBM 159262). a–b. Frontal region. a. Dorsal. b. Lateral. c–d. Major cheliped. c. Mesial. d. Chela, lateral. e–f. Minor cheliped. e. Mesial. f. Chela, lateral. g. Second pereiopod, lateral. h–i. Third pereiopod. h. Lateral. i. Distal propodus and dactylus, lateral. j. Fourth pereiopod, lateral. k. Fifth pereiopod, propodus and dactylus, lateral. Scale bars: a–e, g–h, j=1mm; f, i, k=0.5mm.