Nanhaipotamon wupingense Cheng, Yang, Zhong & Li, 2003

Huang, Chao, Wong, Kai Chin & Ahyong, Shane T., 2018, The freshwater crabs of Macau, with the description of a new species of Nanhaipotamon Bott, 1968 and the redescription of Nanhaipotamonwupingense Cheng, Yang, Zhong & Li, 2003 (Crustacea, Decapoda, Potamidae), ZooKeys 810, pp. 91-111 : 101-104

Nanhaipotamon wupingense Cheng, Yang, Zhong & Li, 2003 Figs 6 D–F, 8

Nanhaipotamon wupingense Cheng, Yang, Zhong & Li, 2003: 678, figs 1-8.

Type material.

Neotype: JX 050563, male (22.4 × 18.3 mm), Xiaba (24.89N, 116.05E), Wuping county, Longyan City, Fujian Province, China, coll. X. M. Zhou, May 2007.

Other material examined.

JX 050564, JX 050566, JX 050568-050569, 4 males (16.2 × 13.2 mm, 15.5 × 12.6 mm, 13.0 × 10.9 mm, 14.0 × 11.5 mm), same data as neotype. JX 050565, JX 050567, JX 050570-050576, 9 females (16.1 × 13.2 mm, 13.0 × 10.5 mm, 25.3 × 20.8 mm, 23.4 × 19.5 mm, 24.9 × 20.3 mm, 21.6 × 17.6 mm, 16.9 × 13.7 mm, 14.8 × 11.7 mm, 15.2 × 12.4 mm), same data as neotype.

Description.

Carapace broader than long, width about 1.2 × length (n = 14); regions indistinct, dorsal surface convex; surface generally smooth, pitted, anterolateral region slightly rugose (Fig. 8A). Front deflexed, margin ridged in dorsal view (Fig. 8A). Epigastric cristae low, separated by narrow gap (Fig. 8A). Postorbital cristae sharp, laterally expanded, almost confluent with epibranchial teeth and epigastric cristae (Fig. 8A). Branchial regions slightly swollen (Fig. 8A, B). Cervical groove shallow (Fig. 8A). Mesogastric region slightly convex (Fig. 8A). External orbital angle sharply triangular, outer margin gently convex, separated from anterolateral margin by conspicuous gap (Fig. 8A, B). Epibranchial tooth small, granular, indistinct (Fig. 8A, B). Anterolateral margin cristate, lined with 17-20 granules, less distinct in some larger specimens; curved inward posteriorly (Fig. 8A). Posterolateral surface with low, oblique striae, converging towards posterior carapace margin (Fig. 8A). Orbits large; supraorbital, infraorbital margins cristate (Fig. 8B). Sub-orbital, pterygostomial and sub-hepatic regions covered with numerous rounded granules (Fig. 8B). Epistome posterior margin narrow; median lobe broadly triangular, lateral margins slightly sinuous (Fig. 8B).

Maxilliped III merus about as wide as long; ischium width about 0.7 × length; merus subtrapezoidal, with median depression; ischium subtrapezoidal, with distinct median sulcus, mesial margin rounded. Exopod reaching to proximal one-third of merus; flagellum short.

Chelipeds (pereiopod I) unequal (Fig. 8A); less inflated in females. Merus trigonal in cross section; margins crenulated, dorsal-outer surface granulated (Fig. 8A). Carpus with sharp spine at inner-distal angle, spinule at base (Fig. 8A). Major cheliped palm length about 1.3 × height (n = 1) in males, 1.3-1.4 × height (n = 4) in females; dactylus about 1.0 × palm length (n = 1) in males, 1.0-1.1 × palm length (n = 4) in females. Palm surface pitted. Dactylus as long as pollex ( Cheng et al. 2003: fig. 1). Occlusal margin of fingers with irregular blunt teeth; slight gape when closed.

Ambulatory legs (pereiopods II–V) slender, setae short, very sparse (Fig. 8A). Pereiopod III merus 0.6 × carapace length (n = 3) in males, 0.6-0.7 × carapace length (n = 7) in females (Fig. 8A). Pereiopods V propodus 2.3-2.4 × as long as broad in males (n = 3), 2.3-2.4 × as long as broad in females (n = 5), shorter than dactylus (Fig. 8A).

Male thoracic sternum generally smooth; anterior thoracic sternum (sternites I–IV) narrow, width about 1.5 × length; sternites I, II forming triangular structure; demarcation between sternites II, III complete; sternites III, IV fused with vestigial median suture (Fig. 8C). Male sterno-pleonal cavity reaching anteriorly beyond level of posterior articular condyle of cheliped coxa (Fig. 8C); deep median longitudinal groove between sternites VII, VIII (Fig. 8D). Male pleonal locking tubercle positioned at mid-length of sternite V (Fig. 8D). Female vulva ovate, not reaching the sutures of sternites V/VI or VI/VII, positioned closely to one another (Fig. 8F).

Male pleon triangular, lateral margins almost straight; somites III–VI progressively narrower; somite VI width 2.1-2.2 × length (n=2); telson width 1.2-1.3 × length (n=2); apex rounded (Fig. 8C). Female pleon broadly ovate (Fig. 8E).

G1 slender; in-situ, tip of terminal segment exceeding pleonal locking tubercle, reaching suture between thoracic sternites IV/V (Fig. 8D, G1 not flat against the body); subterminal segment length about 2.7 × length of terminal segment; subterminal segment tapering posteriorly; terminal segment large, distally expanded, anterior margin laminar, convex anterior margin next to the tip high, tip blunt (Fig. 6D, E). G2 subterminal segment about 2.1 × length of flagelliform distal segment; exopod absent (6F).

Distribution.

Currently only known from Xiaba, Wuping County, Longyan City, Fujian.

Remarks.

The original description of Nanhaipotamon wupingense is brief and minimally illustrated ( Cheng et al. 2003), neither describing nor figuring details of the carapace physiognomy and pterygostomial ornamentation, which are diagnostic differences between N. wupingense and N. macau sp. n. Although the gonopods of N. wupingense were described and figured, and were distinctive at the time of original description, they are similar to that to the newly discovered N. macau sp. n. As such the type account of N. wupingense could apply equally to N. macau sp. n. Unfortunately, the type material of N. wupingense is now lost: according to the first author of N. wupingense , the type material of N. wupingense , which was originally deposited in Fujian Research Institute of Parasite Disease, Fuzhou, Fujian Province, was lost during relocation (YZ Cheng, pers. comm.). Therefore, in order to fix the identity of N. wupingense and allow adequate characterization of both species, we hereby designate a neotype for N. wupingense in accordance to ICZN (1999: art. 75.3). The neotype of N. wupingense (male, 22.4 × 18.3 mm, JX 050563) and other examined specimens of the species were collected from the original type locality. The neotype G1 corresponds well to that originally described and figured for N. wupingense , although we note some minor differences in morphometrics compared to the original type description ( Cheng et al. 2003). The G1 subterminal/terminal segment length ratio of N. wupingense is 3.0 according to Cheng et al. (2003), but, we measure the ratio at 2.7 in the neotype (Fig. 6D) and 2.6 based on the illustration of the G1 of the holotype ( Cheng et al. 2003: fig. 7). The G2 subterminal/terminal segment length ratio of N. wupingense is inconsistently recorded in Cheng et al. (2003): 1.8 in the Chinese description, erroneously as 2.7 in the English abstract, and 2.0 if based on the figure of the holotype G2 ( Cheng et. al. 2003: fig. 6). This ratio could not be measured for the neotype as the G2 terminal segment broke off inside the G1 during dissection, although the ratio in JX 050564, a sub-adult, is 2.2 (Fig. 6F). The G1 is not fully developed in this specimen (Fig. 6E).