Arquatopotamon jizushanense Chu, Zhou & Sun, 2017, sp. n.

Arquatopotamon jizushanense sp. n.

(FigS. 1–6)

Material examined. Holotype: male (adult), 19.4 × 16.4 mm, NNU 160506, Shiqian Village (25°56’15’’ N, 100°24’19’’ E, 1778 m aSl), JizuShan Town, Binchuan County, Dali City in Yunnan ProVince, coll. Kelin Chu, Pengfei Wang & Hongying Sun, 2 May 2016. ParatypeS: female (adult), 22.3 × 18.5 mm, NNU 160510, Same data aS holotype (allotype); 2 maleS (adult), 20.1 × 16.6 mm, NNU 160507; 18.3 × 15.5 mm, NNU 0 90808, Same data aS holotype.

Diagnosis. AS for genuS.

Description. Carapace about 1.2 timeS broader than long, Subquadrate, flat, dorSal Surface gently conVeX longitudinally, punctate, glabrouS; regionS diStinctly defined; epibranchial region rugoSe, meSogaStric region Slightly conVeX (Fig. 1 A). CerVical grooVe Shallow, H-Shaped grooVe between gaStric and cardiac regionS diStinct (Fig. 1 A). PoStfrontal lobe Slightly conVeX, poStorbital creSt indiStinct, poStorbital region Slight concaVe (Fig. 1 A, B). Frontal region defleXed downwardS, anterior border emarginated medially (Fig. 1 B). DorSal orbital margin ridged, eXternal orbital angle triangular, outer margin lined with 4 Small granuleS (Fig. 1 B). Anterolateral margin criState, epibranchial tooth pointed, diStinct, clearly demarcated from eXternal orbital tooth (Fig. 1 A).

Third maXilliped meruS about 1.1 timeS aS broad aS long, trapezoidal, with median depreSSion, tip of the meruS triangular Shaped; iSchium about 1.4 timeS aS long aS broad, rectangular, with diStinct median SulcuS; eXopod reaching proXimal 1/4 of meruS length, without flagellum (Fig. 1 B, 2B).

ChelipedS Slightly unequal; meruS trigonal in croSS-Section; marginS crenulated, carpuS with Sharp Spine on inner diStal angle, with Spinule at baSe (Fig. 1 A, C, 2A). Outer SurfaceS of manuS of major chela Smooth, about 1.5 timeS aS long aS high, Slightly longer than moVable finger, gape narrow when fingerS cloSed, cutting edge lined with rounded, blunt teeth, diStal part of cutting edge Sharp and without teeth (Fig. 1 C, 2A). Ambulatory legS Slender, SurfaceS Smooth; dactyluS Slender, with denSe Spinule, Second ambulatory leg meruS about 1.5 timeS aS long aS dactyluS; laSt leg with propoduS about 1.4 timeS aS long aS broad, Slightly Shorter than dactyluS (Fig. 1 A).

Male abdomen broadly triangular, third Somite wideSt; SiXth Somite width 2.2 timeS length, telSon broadly triangular, with about 1.6 timeS aS broad aS long (Fig. 1 C, 3B). Male thoracic Sternum Smooth; median grooVe of male thoracic Sternum deep; interruption between SutureS of SterniteS 4/5, 5/6, 6/7 broad; median longitudinal Suture between SterniteS 7 and 8 moderately long (Fig. 3 A). G1 long, diStal part of Subterminal, terminal Segment arch Shaped (meSioVentral View; Fig. 2 E), tip of terminal Segment reaching Suture between thoracic SterniteS 4/ 5 in situ (Fig. 3 A); Subterminal Segment about 1.9 timeS aS long aS terminal Segment; terminal Segment tongue-Shaped, diStinctly curVed Ventrally (Ventral View) (Fig. 2 D, E, F and G). G2 Slightly longer than G1, baSal Segment about 2.6 timeS aS long aS diStal Segment (Fig. 2 C).

Female abdomen longitudinally elongated, oVate; SiXth Somite about 3.3 timeS aS broad aS long, telSon Semicircular, about 2.4 timeS aS broad aS long (Fig. 3 D). Female gonopore on thoracic SterniteS 5/6, reaching Suture between thoracic SterniteS 4/ 5 in situ, deep, without operculum, poSterior margin with V-Shaped notch, anterior portion with protuberance (Fig. 3 C, D). The poSteromedial of female gonopore with domed protuberance on thoracic Sternite 6 (Fig. 3 C, D).

Distribution and habitat. Arquatopotamon jizushanense gen. n., sp. n. waS found under StoneS in Small hill StreamS in Shiqian Village (25°56’15’’ N, 100°24’19’’ E), JizuShan Town, Binchuan County, Dali City in Yunnan ProVince, China (Fig. 5 A, B); at an altitude of 1778 m. No other potamidS were obSerVed at the type locality.

Live coloration. Carapace iS uSually dark brown, whereaS chelipedS and ambulatory legS are reddiSh brown to purple in life (Fig. 5 B).

Etymology. Arquatopotamon jizushanense gen. n., sp. n. iS named after the type locality, JizuShan Town in Yunnan ProVince, China.