Songpotamon funingense gen. et, 2023

Shi, Boyang, Pan, Da & Sun, Hongying, 2023, A taxonomic revision of the freshwater crab genus Parvuspotamon Dai & Bo, 1994 (Decapoda, Brachyura, Potamidae), with descriptions of a new genus and two new species, ZooKeys 1183, pp. 13-38 : 13

publication ID	https://dx.doi.org/10.3897/zookeys.1183.109948
publication LSID	lsid:zoobank.org:pub:DA6935B9-D9E1-4B0B-8686-7B661CB9140E
DOI	https://doi.org/10.5281/zenodo.10170920
persistent identifier	https://treatment.plazi.org/id/8C1EEA1D-F6D9-4256-B0D4-1599AA753C99
taxon LSID	lsid:zoobank.org:act:8C1EEA1D-F6D9-4256-B0D4-1599AA753C99
treatment provided by	ZooKeys by Pensoft
scientific name	Songpotamon funingense gen. et
status	sp. nov.

Treatment

Songpotamon funingense gen. et sp. nov.

Figs 5 View Figure 5 , 6 View Figure 6 , 9A-C View Figure 9 , 10A, B View Figure 10

Type material.

Holotype. China • ♂, 27.2 × 21.9 mm; Yunnan Province, Wenshan Prefecture, Funing County, Tianwan Township; 23.20°N, 104.87°E; altitude 880 m asl.; 22 Oct. 2020; Boyang Shi, Ruxiao Wang, and Hongying Sun leg.; GenBank: OR469050; NNU-167462-01.

Paratype. China • ♂, 25.2 × 20.9 mm; same collection data as for holotype; GenBank: OR469051; NNU-167462-02 • ♂, 26.6 × 21.0 mm; same collection data as for holotype; GenBank: OR469057; NNU-167462-03 • ♂, 23.5 × 19.1 mm; same collection data as for holotype; GenBank: OR469058; NNU-167462-04 • ♀, 22.6 × 18.0 mm; same collection data as for holotype; NNU-167462-05 • ♀, 24.6 × 19.7 mm; same collection data as for holotype; NNU-167462-06 • ♂, 22.2 × 17.8 mm; Yunnan Province, Wenshan Prefecture, Funing County, Longbo Township; 23.31°N, 105.46°E; altitude 1611 m asl.; 24 Oct. 2020; Boyang Shi, Ruxiao Wang, and Hongying Sun leg.; GenBank: OR469054; NNU-167533-01 • ♂, 21.5 × 17.7 mm; same collection data as for NNU-167533-01; GenBank: OR469055; NNU-167533-02 • ♀, 20.8 × 16.4 mm; same collection data as for NNU-167533-01; NNU-167533-03.

Diagnosis.

Medium sized (adult carapace width 21-27 mm, n = 9). Carapace broader than long, ovate; dorsal surface convex, smooth, pitted, regions not clear; branchial regions swollen (Fig. 5A View Figure 5 ). Postorbital and epigastric cristae low, not confluent, separated by weak shallow groove (Fig. 5A View Figure 5 ); epigastric cristae weakly developed, straight, separated by shallow inverted Y-shaped groove; postorbital cristae low, rugose (Fig. 5A View Figure 5 ). External orbital angle bluntly triangular, outer margin convex, separated from anterolateral margin of carapace by shallow cleft (Fig. 5A View Figure 5 ). Anterolateral margin of carapace convex, generally smooth, weakly cristate; posterolateral margins gently converging, smooth (Fig. 5A View Figure 5 ). Orbits large; supraorbital and infraorbital margins smooth (Fig. 5B View Figure 5 ); sub-orbital, sub-hepatic and pterygostomial regions smooth or weakly rugose (Fig. 5B, C View Figure 5 ). Antennular fossae rectangular in anterior view; median lobe of epistome posterior margin low, rounded (Fig. 5B View Figure 5 ). Exopod of third maxilliped reaching beyond anterolateral corner of ischium, without flagellum (Fig. 6C View Figure 6 ). Thoracic sternites 3/4 in male fused except for relatively deep, incomplete groove demarcating suture (Figs 5C View Figure 5 , 6E, G View Figure 6 ). Vulvae transversely ovate, closely located to each other, touching suture of sternites 5/6, opened obliquely ~ 45° upwards (Fig. 6H View Figure 6 ). Male pleon narrowly triangular; somite 6 relatively narrow, width ~ 2.4 × as length (Fig. 5C View Figure 5 ). G1 slender, almost reaching pleonal locking tubercle in situ (Figs 6G View Figure 6 , 9A, B View Figure 9 , 10A, B View Figure 10 ); subterminal segment stout, sinuous, inner margin concave; terminal segment subconical, bent at ~ 45° outwards, relatively short, ~ 0.4 × length of subterminal segment, with distinct groove for G2 on ventral side, tip subtruncate, recurved upwards (Figs 9A, B View Figure 9 , 10A, B View Figure 10 ). G2 longer than G1; terminal segment relatively short; subterminal segment ~ 5 × length of terminal segment (Fig. 9C View Figure 9 ).

Description.

Medium sized (adult carapace width 21-27 mm, n = 9). Carapace broader than long, ovate; dorsal surface convex transversely, longitudinally, smooth, pitted, regions not clear; branchial regions swollen, smooth (Fig. 5A View Figure 5 ). Postorbital and epigastric cristae inconspicuous, not confluent, separated by weakly shallow groove (Fig. 5A View Figure 5 ); epigastric cristae weakly developed, straight, separated by shallow Y-shaped groove; postorbital cristae low, rugose, reaching epibranchial tooth (Fig. 5A View Figure 5 ). Cervical groove indistinct (Fig. 5A View Figure 5 ). External orbital angle bluntly triangular, outer margin straight, with shallow cleft demarcating it from epibranchial tooth; epibranchial tooth weakly developed (Fig. 5A View Figure 5 ). Anterolateral margin convex, smooth, weakly cristate; posterolateral margin gently concave, smooth, converging towards posterior carapace margin (Fig. 5A View Figure 5 ). Orbits large; supraorbital and infraorbital margins smooth; sub-orbital, sub-hepatic, and pterygostomial regions relatively smooth or weakly rugose (Fig. 5B, C View Figure 5 ). Antennular fossae rectangular in anterior view; median lobe of epistome posterior margin low, rounded (Fig. 5B View Figure 5 ). Third maxilliped with rhombus ischium; exopod of third maxilliped reaching beyond anterolateral corner of ischium, without flagellum (Fig. 6C View Figure 6 ).

Chelipeds unequal (Figs 5A, C View Figure 5 , 6A, B View Figure 6 ). Merus trigonal in cross section; margins crenulated (Fig. 5A, C View Figure 5 ). Carpus with sharp spine at inner-distal angle (Fig. 5A, C View Figure 5 ). Major cheliped palm length ~ 1.4 × as height (Fig. 6B View Figure 6 ). Occlusal margin of fingers with sharp teeth; distinct gape when closed (Fig. 6B View Figure 6 ).

Ambulatory legs not distinctly elongated, dactyli slender (Figs 5A, C View Figure 5 , 6D View Figure 6 ); second pair longest, last pair shortest (Fig. 5A, C View Figure 5 ). Outer surface of merus slightly rugose, dorsal margin weakly serrated, without subdistal tooth, length ~ 3.7 × as width (Fig. 6D View Figure 6 ).

Male thoracic sternum generally smooth, weakly pitted; sternites 1/2 fused to form a triangular structure (Figs 5C View Figure 5 , 6E, G View Figure 6 ); sternites 2/3 demarcated by horizontal groove; sternites 3/4 fused except for relatively deep, incomplete groove demarcating suture (Figs 5C View Figure 5 , 6E, G View Figure 6 ); median longitudinal suture of sternites 7/8 deep (Fig. 6E, G View Figure 6 ). Vulvae transversely ovate, closely located to each other, touching suture of sternites 5/6, opened obliquely ~ 45° upwards, posteromesial margin with low raised rim (Fig. 6H View Figure 6 ).

Male pleon narrowly triangular; telson relatively broad, lateral margins slightly convex, width ~ 1.2 × as length (Figs 5C View Figure 5 , 6E View Figure 6 ); somite 6 broadly rectangular, width ~ 2.4 × as length; suture between somites 6/7 sinuous; somites 3-5 trapezoidal, gradually decreasing in width; somite 2 trapezoidal, reaching to bases of coxae of fourth ambulatory legs; thoracic sternite 8 not visible when pleon closed (Figs 5C View Figure 5 , 6E View Figure 6 ). Female pleon ovate, covering most of thoracic sternum (Fig. 6F View Figure 6 ).

G1 slender, almost reaching pleonal locking tubercle in situ, with terminal and subterminal segments clearly demarcated (Figs 6G View Figure 6 , 9A, B View Figure 9 , 10A, B View Figure 10 ); subterminal segment stout, sinuous, distal part prominently narrow, inner margin concave (Figs 9A, B View Figure 9 , 10A, B View Figure 10 ); terminal segment slender, subconical, bent at ~ 45° outwards, relatively short, ~ 0.4 × length of subterminal segment, outer margin slightly convex, inner margin straight, with distinct groove for G2 on ventral side, tip subtruncate, recurved upwards (Figs 9A, B View Figure 9 , 10A, B View Figure 10 ). G2 longer than G1, terminal segment relatively short; subterminal segment ~ 5 × length of terminal segment (Fig. 9C View Figure 9 ).

Etymology.

The species is named after Funing County, the type locality of the new species in the Yunnan Province of China.

Colour in life.

Carapace and chelipeds are generally bright orange to red with purplish brown ambulatory legs in mature individuals. Generally purplish brown all over with bright orange tips of the chelipeds in smaller individuals.

Habitat.

This new semi-terrestrial species digs and inhabits mud burrows close to small hill streams and seeps.

Remarks.

The new species most closely resembles S. malipoense gen. et sp. nov., in general carapace morphology, especially in possessing the relatively narrower male pleonal somite 6, the recurved tip of the G1 terminal segment, and the distinct and entire groove for the G2 on the ventral side of the G1 terminal segment. Songpotamon funingense gen. et sp. nov., however, can be separated from S. malipoense gen. et sp. nov. by the following characters: 1) anterolateral margins of the carapace generally smooth (Fig. 5A View Figure 5 ) (vs with small granules; Fig. 7A View Figure 7 ); epigastric cristae straight in dorsal view and separated from each other by a shallow inverted Y-shaped groove (Fig. 5A View Figure 5 ) (vs oblique in dorsal view and separated from each other by a relatively deep inverted Y-shaped groove; Fig. 7A View Figure 7 ); male thoracic sternites 3/4 with relatively deep groove demarcating suture (Figs 5C View Figure 5 , 6E, G View Figure 6 ) (vs relatively shallow; Figs 7C View Figure 7 , 8E, G View Figure 8 ); vulvae opening obliquely ~ 45° upwards (Fig. 6H View Figure 6 ) (vs opening inwards; Fig. 9H View Figure 9 ); G1 subterminal segment relatively stouter, with the inner margin concave (Figs 9A, B View Figure 9 , 10A, B View Figure 10 ) (vs relatively slenderer, with the inner margin almost straight; Figs 9D, E View Figure 9 , 10C, D View Figure 10 ); and G1 terminal segment strongly bent at ~ 45° outwards (Figs 9A, B View Figure 9 , 10A, B View Figure 10 ) (vs gently curved at ~ 30° outwards; Figs 9D, E View Figure 9 , 10C, D View Figure 10 ).

The new species is also morphologically similar to S. dixuense comb. nov. in the weakly developed epibranchial tooth, the relatively smooth sub-orbital, sub-hepatic, and pterygostomial regions, and the sinuous subterminal segment of the G1. Songpotamon funingense gen. et sp. nov., however, can be distinguished from S. dixuense comb. nov. by the following characters: antennular fossae subrectangular (Fig. 5B View Figure 5 ) (vs slit-like); male pleonal somite 6 relatively narrower (Fig. 5C View Figure 5 ) (vs relatively broader); vulvae opening distinctly oblique ~ 45° upwards (Fig. 6H View Figure 6 ) (vs opening slightly oblique ~ 30° upwards); G1 subterminal segment relatively stouter (Figs 9A, B View Figure 9 , 10A, B View Figure 10 ) (vs relatively slenderer); and G1 terminal segment relatively strongly bent at ~ 45° outwards (Figs 9A, B View Figure 9 , 10A, B View Figure 10 ) (vs gently curved at ~ 30° outwards) (cf. Naruse et al. 2018: figs 24B, 26, 27).