Aparapotamon huizeense, Tan & Zhou & Zou, 2021

Tan, Qi-Hong, Zhou, Xiao-Juan & Zou, Jie-Xin, 2021, Two new species of freshwater crab of the genus Aparapotamon Dai & Chen, 1985 (Crustacea, Brachyura, Potamidae) from Yunnan, China, ZooKeys 1056, pp. 149-171 : 149

publication ID	https://dx.doi.org/10.3897/zookeys.1056.63755
publication LSID	lsid:zoobank.org:pub:569F6C2B-8F21-4048-B8D8-85525264217C
persistent identifier	https://treatment.plazi.org/id/9B44A1C4-162B-4DB0-BE6C-DCE5124412B0
taxon LSID	lsid:zoobank.org:act:9B44A1C4-162B-4DB0-BE6C-DCE5124412B0
treatment provided by	ZooKeys by Pensoft
scientific name	Aparapotamon huizeense
status	sp. nov.

Treatment

Aparapotamon huizeense View in CoL sp. nov.

Figures 5 View Figure 5 , 6 View Figure 6 , 7 View Figure 7 , 8 View Figure 8

Material examined.

Holotype: NCU MCP 179801, 1♂ (25.9 × 21.2 mm), China, Yunnan Province, Qujing City, Huize County, Nagu Town , Zebu Village , 26°30'41"N, 103°10'25"E, alt. 1954 m, 25 Aug 2011, Yue Huang leg. GoogleMaps Paratypes: NCU MCP 179802, 1♂ (26.9 × 21.9 mm) and NCU MCP 179803-179808, 6♀♀ (31.0 × 24.8 mm, 30.7 × 23.6 mm, 27.3 × 21.5 mm, 23.5 × 18.4 mm, 25.5 × 20.5 mm, 29.8 × 22.6 mm), same data as holotype GoogleMaps .

Diagnosis.

Carapace trapezoidal, dorsal surface slightly convex, regions defined. External orbital angle round, separated from anterolateral margin, postorbital cristae convex, postfrontal lobe prominent. Cervical groove shallow, H-shaped groove distinct, especially in female specimen. Epibranchial tooth distinct, especially in female specimen. Third maxilliped exopod without flagellum. Ambulatory legs slender. Male pleon broad triangular, telson triangular, apex rounded. Vulva ovate, covering anterior half of sternite 6, with the posterior margin distinctly convex. G1 very slender, dorsal lobe well developed, exceeding suture 4/5 in situ, G2 basal segment ovate, tip of terminal segment round.

Description.

Carapace width 1.25 × length (n = 8), regions distinctly defined; dorsal surface slightly convex, anterolateral and frontal region covered with conspicuous round granules (Fig. 5A, B View Figure 5 ). External orbital angle triangular, round, separated from anterolateral margin by deep notch (Figs 5A-C View Figure 5 , 7A View Figure 7 ). Postorbital cristae convex, not continuous to epibranchial tooth; postfrontal lobe prominent, separated medially by a Y-shaped groove extending to the frontal region (Figs 5A, B View Figure 5 , 7A View Figure 7 ). Cervical groove shallow; H-shaped gastro-cardiac groove distinct, especially in female specimen (Figs 5A, B View Figure 5 , 7A View Figure 7 ). Epibranchial tooth sharp, distinct, especially in female specimen; anterolateral margin cristae distinct, curved inwards posteriorly, lined with approximately 10-13 ambiguous granules; posterolateral surface smooth, with some inconspicuous oblique striae, converging towards posterior carapace margin (Figs 5A, B View Figure 5 , 7A View Figure 7 ). Orbits and eyes medium-size; supraorbital margin ridged, infraorbital margins cristate, minutely granulated (Fig. 5C View Figure 5 ). Sub-orbital smooth, pterygostomial and sub-hepatic regions covered with sparse round granules (Fig. 5C View Figure 5 ). Epistome posterior margin median lobe broad triangular, lateral margin with small projection (Fig. 5C View Figure 5 ).

Third maxilliped exopod without flagellum, claviform, reaching proximal 1/3 of merus lateral margin (Figs 5C View Figure 5 , 6B View Figure 6 ). Ischium about 1.4 times as long as broad, rectangular, longitudinal median sulcus indistinct (Fig. 6B View Figure 6 ). Merus about 1.3 times as broad as long, subquadrate, median slightly depressed (Figs 5C View Figure 5 , 6B View Figure 6 ). Chelipeds unequal in both adult male and female, palm of larger cheliped length 1.4 × height (n = 8); dactylus 0.6 × palm length (n = 8); slightly shorter than pollex (Figs 5A View Figure 5 , 6A View Figure 6 ). Merus outer surface punctate; carpus surface covered with several prominent granules and sharp spine at inner-distal angle (Figs 5A View Figure 5 , 7A View Figure 7 ). Occlusal margins of fingers of adult male with numerous round blunt teeth, with narrow gap when fingers closed (Fig. 6A View Figure 6 ). Ambulatory legs slender; second ambulatory legs longest; fourth ambulatory leg propodus 1.9 × as long as broad (n = 8), shorter than dactylus, which accompanied with several thorn-like setae (Figs 5A View Figure 5 , 6D View Figure 6 ).

Male thoracic sternum punctate, formed by tidy depression; sternites 1-4 broad, sternites 1/2 completely continuous; suture 2/3 complete, transverse; suture 3/4 visible, mesially reaching distolateral part of sterno-pleonal cavity (Fig. 6C, E View Figure 6 ). Male sterno-pleonal cavity deep; median longitudinal groove between sternites 7, 8 long; male pleonal locking tubercle barely visible, almost middle of sternite 5 (Fig. 6F View Figure 6 , arrow). Male pleon broad triangular (Fig. 6C View Figure 6 ); telson triangular, apex rounded, width 1.4 × length in males (n = 2), 2.5 × in females (n = 6); somite 6 trapezoidal, width 2.3 × length in males (n = 2), 3.0 × in females (n = 6) (Figs 6C View Figure 6 , 7B View Figure 7 ). Vulva medium-size, ovate, superior margin reaching suture 5/6 in situ, opening inward, posterior margin distinctly convex, the sternal vulvar cover broadly triangular and relatively low (Fig. 7C View Figure 7 ).

G1 very slender; terminal segment claviform, slightly bent distally, inner margin arc-shaped, outer margin straightly, dorsal lobe well developed and gonopod pore located in it (Fig. 8A-D View Figure 8 ); exceeding suture4/5 in situ (Fig. 6F View Figure 6 ); clear boundary between terminal segment and subterminal segment, the latter length about 0.9 × length of terminal segment (Fig. 8A, C View Figure 8 ). G2 basal segment ovate, about 1.9 × length of terminal segment, tip of terminal segment round (Fig. 8E View Figure 8 ).

Etymology.

The species is named after the type locality, Huize County, Qujing City, Yunnan Province.

Distribution.

The new species is presently known only from the type locality presently, Huize County, Qujing City, Yunnan Province.

Remarks.

Aparapotamon huizeense sp. nov. closely resembles A. grahami in the general carapace morphology and G1 structure. However, A. huizeense sp. nov. can be distinguished from A. grahami by the following characters: G1 exceeding suture 4/5 in situ (Fig. 6F View Figure 6 ) [vs. reaching pleonal locking tubercle but not reaching suture 4/5 in situ ( Dai 1999: fig. 187)]; and the G1 is very slender, terminal segment slightly bent distally, dorsal lobe well developed (Fig. 9B View Figure 9 ) [vs. slender, terminal segment without bending (Fig. 9J View Figure 9 ), dorsal lobe variably developed]. A. huizeense sp. nov. is also similar to A. huiliense . But, in A. huiliense , G1 extends to pleonal locking tubercle but not exceeding suture 4/5 in situ ( Dai 1999: fig. 189) and its dorsal lobe roundly developed (Fig. 9K View Figure 9 ). For detailed differences between this new species and congeners, see Table 2 View Table 2 .