Thor hainanensis Xu & Li, 2014

Xu, Peng & Li, Xin-Zheng, 2015, Report on the Hippolytidae Bate (sensu lato) from China seas, Zoological Systematics 40 (2), pp. 107-165 : 157-161

Thor hainanensis Xu & Li, 2014 ( Figs 32–34 )

Thor hainanensis Xu & Li, 2014b: 394 , figs. 1–5.

Material examined. MBM136607 , 1 ovig. ♀ (cl 1.80 mm), Hainan, Sanya , intertidal, 1997-3-5, no . CJ97 C-224, coll. Xin-Zheng Li ; MBM136405 , 1 ♂ (cl 1.90 mm), Hainan, Qionghai , intertidal, 1992-4-4, no.92C-1471, coll. Xin-Zheng Li ; MBM136387 , 5 ovig. ♀ (cl 1.70–2.10 mm), Hainan, Lingao , intertidal, 1990-12-2, no.90C-353, coll. Hui-Lian Chen ; MBM136589 , 4 ovig. ♀ (cl 1.80–1.90 mm), Hainan, Sanya , intertidal, 1997-3-1, no . CJ97 C-119, coll. Xin-Zheng Li ; MBM136394 , 5 ovig. ♀ (cl 1.80–2.00 mm), Hainan, Lingshui , 1992-3-26, no.92C-160D, coll. Xin-Zheng Li ; MBM136395 , 5 ♂ (cl 1.71–2.36 mm), 8 ovig. ♀ (cl 1.87–2.65 mm), Hainan, Sanya, Yalong Gulf, Yezhu Island , 1992-3-19, diving, 3–7 m, no.92C-062B, coll. Xin-Zheng Li.

Description. Small hippolytid shrimp without supraorbital spine. Rostrum about half length of carapace, nearly straight, slightly descending, reaching but not exceeding basal segment of antennular peduncle; dorsal margin with three teeth, posterior one on carapaceposterior to margin of orbit; ventral margin armed with only one subterminal tooth, giving rostrum bifid appearance; lateral carina feebly developed. Carapace with inferior orbital angle slightly produced, subacute; antennal tooth moderately developed; pterygostomian tooth minute; anterolateral margin between antennal tooth and pterygostomian tooth obscurely angulate.

© Zoological Systematics, 40 (2): 107–165

Abdomen rounded dorsally. Pleurae of fourth and fifth abdominal somites each with small posteroventral tooth. Sixth somite 1.9 times as long as fifth mid-dorsal length. Telson about 1.2 times longer than sixth abdominal somite; dorsal surface with 3–5 pairs of dorsolateral spines and 3 pairs of terminal spines, lateral pair similar to dorsolateral series.

Eye subpyriform, pigmented; cornea with distinct ocellar spot, shorter than stalk. Antennular peduncle reaching distal 0.4 of antennal scale. Basal segment with strong subdistal, ventromesial tooth; sharp stylocerite reaching slightly beyond

© Zoological Systematics, 40 (2): 107–165 distal margin of second segment, armed with little indistinct tooth near proximal end of lateral margin; second segment with curved lateral spine reaching beyond mid-length of distal segment; third segment with subtriangular dorsal scale. Outer flagellum stout and heavily setose. Inner flagellum slender, elongate, with 23–28 segments. Antennal peduncle with basicerite bearing strong distal, ventrolateral tooth, dorsodistal angle bluntly produced. Carpocerite overreaching second segment of antennular peduncle. Antennal scale shorter than length of carapace, 2.4 times as long as wide; lateral margin faintly concave, with distolateral tooth exceeded by lamina.

Mouthparts typical of genus. Mandible without palp; incisor process slender, with series of four subequal, tiny, distal teeth; molar process stout.

Third maxilliped long and slender, somewhat beyond antennal scale; ultimate segment 4.3 times longer than penultimate segment, with corneous spines distally; antepenultimate segment subequal in length to ultimate segment, distoventral margin with small spine. Exopod exceeding middle of antepenultimate segment; epipod present.

First pereopod with strap-like, terminally hooked epipod; moderately stout, falling short of distalmargin of antennal scale. Chela about 1.2 times longer than carpus, 3.1 times longer than wide; dactylus with bifid tip, slightly longer than half length of palm; palm subcylindrical, 2.1 times as long as wide, fixed finger terminatingin single corneous claw. Carpus 3.1 times longer than wide. Merus subequal in length to carpus, 2.3 times as long as wide. Second pereopod slender and chelate; carpus with six sub-segments, third sub-segment longest. Merus shorter than carpus, 6.3 times longer than width. No epipod.

Third pereopodin female overreaching antennal scale by length of dactylus; biunguiculate dactylus 0.2 times as long as propodus, about 2.6 times longer than high, armed with three accessory spines along entire length of flexor margin; propodus 10 times as long as wide; flexor margin with about 9–10 spinules, spinules increasing in size distally; carpus less than half length of propodus, 2.9–4.2 times longer than wide. Merus about equal topropodus, 5.9 times longer than deep, with 1 or 2 prominent lateral spines distally. Ischium unarmed. Fourth pereopodin female similar to third pereopod, overreaching antennal scale, biunguiculate dactylus armed with 4 accessory spines along entire length of flexor margin; merus with 1 distolateral spine. Third pereopod in male prehensile, subchelate. Dactylus with bifid tip and manyclosely appressed spinules on flexor margin; propodus more than twice as long as dactylus, distal third of flexor margin with densely spinules; carpus less than half as long as propodus; merus slightly shorter than propodus, armed with strong spine near distal end of lateral surface. Fourth pereopod in male similar to third pereopod, prehensile, subchelate; merus also armed with one distolateral spine. Fifth pereopod with 0 or 1 meral spine. Pleopods without special features. Second pleopod in male with appendix masculine moderately stout, almost 6 times as long as wide, about 0.9 length of appendix interna, bearing about 5 long stiff setae.

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Uropods longer than telson, fringed with setae; outer branch of uropod with fixed tooth and movable spine along suture.

© Zoological Systematics, 40 (2): 107–165

Coloration in life. Unknown.

Distribution. Only known from the type locality, Hainan Island; 2– 15 m.

Remarks. The distinct morphological character of the species is the presence of an epipod on the first pereopod. The prehensile and subchelate fourth pereopod of male is also rare and unique in the genus.

Figures

Fig. 32. Thor hainanensis Xu & Li, 2014, ovigerous female (cl 1.8mm) (After Xu & Li, 2014b). A. Body, lateral view; B. Rostrum, lateral view. Scale bars=1mm.

Fig. 33. Thor hainanensis Xu & Li, 2014, ovigerous female (cl 1.8 mm) (After Xu & Li, 2014b). A. Antennule, dorsal view; B. Telson and uropod, dorsal view; C. Left mandible, external view; D. Left maxillule, external view; E. Left maxilla, external view; F. Left firstmaxilliped, external view; G. Left second maxilliped, external view; H. Left third maxilliped, lateral view; I. Left first pereopod, lateral view; J. Left second pereopod, lateral view; K. Left third pereopod, lateral view; L. Left fourth pereopod, lateral view; M. Left fifth pereopod, lateral view. Scale bars=1mm.

Fig. 34. Thor hainanensis Xu & Li, 2014. Male (cl 1.9 mm) (After Xu & Li, 2014b). A. Right third pereopod, lateral view; B. Right fourth pereopod, lateral view; C. Endopod of second pleopod, ventral view. Scale bars=1 mm.