Jianghuaimon dabiense gen. nov. et sp. nov

[Chinese name: kDzü淮ēø]

(Figs. 1–5)

Type material. Holotype: SYSBM002003, male (20.4 × 15.7 mm), Yaoluoping National Nature Reserve (31.17°N, 116.22°E), Huoshan County, Lu’an City, Anhui Province, China, in burrow in mountain seepage, 500–550 m a.s.l., coll. Jun-Da. Zhao, October 2020.

Paratypes: SYSBM002005–002006, 2 males (15.1 × 11.8 mm, 15.2 × 12.1 mm) same data as holotype . SYSBM002007, 1 female (16.4 × 13.0 mm) same data as holotype . SYSBM002004, 1 male (17.4 × 13.4 mm) same data as holotype . SYSBM002008–002009, 1 male (17.5 × 13.2 mm), 1 female (14.8× 11.4 mm), Dabie Mountains National Nature Reserve (30.97°N, 116.04°E), Yingshan County, Huanggang City, Hubei Province, China, under rocks in forest floor near mountain stream, 980–1100 m a.s.l., coll. Jun-Da. Zhao, October 2020. NCU MCP4322, 1 male (21.9 × 16.7 mm) same data as holotype . NCU MCP 4323 1 female (14.9 × 11.9 mm) same data as SYSBM 002008–002009. NNU 20105JD1–20105JD2, 2 males (16.9 × 12.9 mm, 17.3 × 13.3 mm), Foziling Town (31.33°N, 116.23°E), Huoshan County, Lu’an city, Anhui Province, China, under rocks on forest floor near mountain stream, 200–350 m a.s.l., coll. Jun-Da. Zhao, October 2020 .

Description. Carapace broader than long; subquadrate; width 1.3 × length (n = 15); regions clearly demarcated. Dorsal surfaces strongly pitted (Fig.1). Frontal margin ridged in dorsal view (Fig.1). Epigastric cristae rugose, blunt, divided by conspicuous groove (Fig.1, 2A). Postorbital cristae rugose, slightly raised (Figs. 1, 2A). Cervical groove relatively large and deep; H-groove visible (Fig.1). External orbital margin bluntly triangular with nearly no gap with anterolateral margins (Figs. 1, 2A). External orbital tooth small, inconspicuous (Figs. 1,2A). Epibranchial tooth low, blunt (Figs.1,2A). Anterolateral margin ridged, margins slightly trending upwards, with 12–15 granules (Figs.1,2A). Posterolateral margin straight, slightly rugose (Fig.1). Epibranchial region with small, smooth bumps (Fig.1). Orbits medium-sized; supraorbital margin smooth, slightly ridged; infraorbital margins slightly ridged, lined with numerous inconspicuous granules (Figs. 1,2A). Sub-orbital, sub-hepatic and upper parts of pterygostomial regions surface relatively rugose; divided with sutures that are lined with numerous inconspicuous granules (Fig. 2A). Central epistome covered with thick setae (Fig. 2A). Epistomial median lobe narrowly triangular (Fig. 2A).

Maxilliped III merus width about 1.3 × length; ischium width about 0.8 × length; merus pitted, subtrapezoidal with median depression; ischium trapezoidal, inner-upper margin rounded; with distinct median sulcus; exopod reaching to approximal one–eighth of merus height, with long flagellum length nearly same height with merus (Fig. 3A).

TABLE 1.

Chelipeds slightly unequal, surface rugose, finely pitted (Figs. 1, 3F–G). Merus cross section triagonal, margins weakly crenulated, surfaces generally smooth (Figs. 1, 2A). Carpus inner distal angle with sharp spine and blunt spinule at base, surface rugose (Figs. 1, 2A). Male major cheliped palm length about 1.4–1.5 × height (n=3), 1.4 × in females (n=2); dactylus 0.8 × palm length in both sex: males (n=3), females (n=2) (Fig. 3F–G). Palm surface slightly rugose, finely pitted. Inner margin of fingers lined with round, blunt, small to large sized teeth; with small gap when fingers closed (Fig. 3F–G). Pereiopods II–V (first to fourth ambulatory legs) slender (Fig. 1). Pereiopods III the longest; pereiopods V propodus length 1.9–2 × width in males (n = 3) and females (n = 2); dactylus stout, with short, sharp spines on margins (Fig. 1).Male thoracic sternum glabrous, pitted; sternites I–IV wide, width 1.8 × length. Sternites I, II fused, forming a wide triangular shape; sternites II, III fused, separated by a horizontal grove; sternites III, IV fused, with indistinct sulcus (Fig. 2B). Male sternopleonal cavity deep, long, reaching to imaginary line joining medial part of cheliped coxae (Fig. 2B–D); median longitudinal suture between sternites VII and VIII relatively short, shallow, not reaching sternite VI (Fig. 2D). Female vulva ovate, large-sized, opened inwards, oblique to the horizontal axis of pleon, with outer rim; located within sternite suture VI, almost reaching suture V/VI and VI/VII (Fig. 2F).

Pleon and telson broadly triangular in males (Fig. 2C), broadly ovate in females (Fig. 2E). Male pleonites III–VI gradually narrower upward; pleonite VI 2.5 × as broad as long; telson 1.5 × as broad as long, with semicircular apex (Fig. 2C).

G1 generally slender, pointed anterolaterally, long, reaching beyond pleonal locking tubercle while exceeding sternites IV/V suture in situ (Fig. 2D). Subterminal segment 2.0 × as long as terminal segment (n=3), inner margin concave, outer margin convex. Terminal segment large and stout with wide opening at truncate tip, inner margin strongly convex, outer margin strongly concave (Fig. 3C–E, H–I). G2 basal segment subtrapezoid, about 1.5–1.8 × length of flagelliform distal segment (n=4) (Fig. 3B).

Etymology. The species is named after its type locality, the Dabie Mountains.

Distribution. Yaoluoping National Nature Reserve, Foziling Town, Huoshan County, Lu’an City, Anhui Province, China; Dabie Mountains National Nature Reserve, Ying Shan County, Huang Gang City, Hubei Province, China.

Color in life. Generally dark brown to umber. Carapace margins, ambulatory legs and chelipeds with orange and black spots. Propodus of ambulatory legs with wide orange stripe (Fig. 5D). Third maxilliped merus with distinctive goldish oval shaped spot, reaching over to upper ischium in some individuals. Abdomen ivory.

Habitat. Jianghuaimon dabiense gen. nov. et sp. nov. is usually found in burrows or under rocks in mountain seepages and streams (Fig. 5C). The species shows some terrestrial adaptability as evident from them also being found under stones or in dried burrows on land that are relativity distant from the water body (10–20 m). This suggests some plasticity in its habitat choice (Fig. 5B). The species was found within the altitude of 200–1100 m a.s.l. Longpotamon depressum (Dai & Fan, 1979), were observed to be syntopic with Jianghuaimon dabiense gen. nov. et sp. nov. in some aquatic habitats.