Buea bangem Mvogo Ndongo, von Rintelen, Tomedi-Tabi & Cumberlidge, 2020

Buea bangem Mvogo Ndongo, von Rintelen, Tomedi-Tabi & Cumberlidge View in CoL n. sp.

( Figs. 2A, B View Figure 2 , 3C, D View Figure 3 , 4A View Figure 4 , 5A, E, I View Figure 5 , 6G–I View Figure 6 , 7A–C View Figure 7 , 8A, E View Figure 8 )

Type material: Holotype adult male (CW 26.54 mm, CL 18.07 mm, CH 10.16 mm, FW 7.12 mm), Cameroon, Southwest region, Bangem, Bakossi National Park (05°01 ′ 25.5 ′′ N, 09°42 ′ 17.6 ′′ E), 1,253 m asl, 16 March 2017, coll. P. A. Mvogo Ndongo (ZMB Crust. 30325) .

Paratypes: 5 adult males (CW 24.56 mm, CL 16.73 mm, CH 8.92 mm, FW 6.81 mm; CW 24.46 mm, CL 16.24 mm, CH 8.87 mm, FW 7.51 mm; CW 21.20 mm, CL 14.34 mm, CH 8.65 mm, FW 7.17 mm; CW 20.72 mm, CL 14.55 mm, CH 7.99, FW 6.14 mm; CW 20.05 mm, CL 13.82 mm, CH 7.78 mm, FW 6.00 mm) (IFAS-010); 2 subadult males (CW 18.60 mm, CL 13.27 mm, CH 7.23 mm, FW 5.42 mm; CW 16.74 mm, CL 12.43 mm, CH 6.51 mm, FW 5.09 mm), Cameroon, Southwest region, Bangem, Bakossi National Park (05°02 ′ 05.5 ′′ N, 09°41 ′ 57.9 ′′ E), 1,248 m asl, 15 March 2017, coll. P. A. Mvogo Ndongo (IFAS-011).

Diagnosis: Carapace height greatly exceeding FW (CH/FW 1.43, N = 8), anterior carapace surface with fields of granules, carinae; cervical, urogastric, cardiac, branchial grooves all distinct, shallow ( Figs. 2A View Figure 2 , 5E View Figure 5 ); carapace branchiostegal wall with distinct vertical (pleural) groove ( Figs. 2B View Figure 2 , 5A View Figure 5 ). Thoracic sternal sulcus S2/ S3 slightly arched (2B, 5I). Major cheliped dactylus stout, slightly arched, lined by small teeth, with large tooth in middle; major cheliped propodus inferior margin distinctly concave; pollex with 3 evenly-spaced large teeth ( Fig. 3C View Figure 3 ). Lower margin of cheliped merus lined by pointed teeth, distal tooth jagged, largest ( Figs. 2B View Figure 2 , 6G, H View Figure 6 ). Terminal segment (TS) of mandibular palp bilobed, with large distinct anterior lobe (0.4× TS length) ( Fig. 8A View Figure 8 ). G1 TA very long, equal to SS length (TA/SS 1.00) ( Figs. 7A, B View Figure 7 ); G2 TA extremely short (TA/SS 0.12) ( Fig. 7C View Figure 7 ).

Description: Carapace ovoid, height greatly exceeding FW (CH/ FW 1.43, N = 8), medium width (CW/FW 3.73, N = 8), surface texture granular; anterior corners of carapace each with field of carinae; cervical, urogastric, cardiac, branchial grooves all distinct, shallow ( Figs. 2A View Figure 2 , 5E View Figure 5 ). Postfrontal crest clearly defined, lateral ends meeting anterolateral margins at epibranchial teeth ( Figs. 2A View Figure 2 , 5A, E View Figure 5 ). Exorbital tooth small, low; intermediate, epibranchial teeth small, reduced to granule ( Figs. 2A View Figure 2 , 5A View Figure 5 ). Anterolateral margin behind epibranchial tooth granular ( Figs. 2A View Figure 2 , 5A View Figure 5 ). Carapace branchiostegite with longitudinal, vertical sutures dividing wall into suborbital, subhepatic, pterygostomial regions; vertical suture distinct, beginning behind epibranchial tooth ( Figs. 2A View Figure 2 , 5A View Figure 5 ). Mandibular palp 2-segmented; terminal segment (TS) bilobed, with large, distinct a`nterior lobe (0.4× TS length) ( Fig. 8A View Figure 8 ). Third maxillipeds filling entire buccal cavern, except for transversely oval efferent respiratory openings in superior lateral corners, exopod lacking flagellum, ischium with distinct vertical sulcus ( Fig. 8E View Figure 8 ). Sternal sulcus S2/S3, slightly arched, completely crossing sternum; S3/S4 incomplete, reduced to 2 small side notches ( Figs. 2B View Figure 2 , 5I View Figure 5 ); episternal sulci S4/E4, S5/E5, S6/E6 complete, S7/E7 missing ( Figs. 2B View Figure 2 , 5I View Figure 5 ).

Chelipeds of adult male greatly unequal ( Figs. 2A, B View Figure 2 , 3C, D View Figure 3 ). Fingers slim, elongated, major cheliped dactylus, stout, straight, with large pointed tooth in middle, propodus with large rectangular tooth on proximal part, large tooth distally, fingers enclosing oval interspace when closed ( Fig. 3C View Figure 3 ). Minor cheliped with occluding margins of fingers lined by row of small teeth enclosing narrow oval interspace when closed ( Fig. 3D View Figure 3 ). Cheliped carpus with 2 large pointed, unequal teeth, distal tooth broad, proximal tooth smaller ( Fig. 6I View Figure 6 ). Lower margin of merus of major, minor chelipeds with large jagged blunt rectangular tooth followed by row of small stout teeth ( Figs. 2B View Figure 2 , 6G, H View Figure 6 ). Walking legs (pereiopods P2–P5) slender, posterior margins of propodi serrated with small pointed teeth, dactyli tapering, each bearing rows of downward-pointing large sharp spines

( Figs. 2A, B View Figure 2 ). Male pleon large, triangular, sides not indented, bordered by row of setae; telson (A7) large, with rounded distal margin ( Figs. 2B View Figure 2 , 5I View Figure 5 ). G1 TA very long, equal to SS length (TA/SS 1.0), proximal half straight, distal half directed outward ending in short tip, with long setae along ventral margins ( Figs. 7A, B View Figure 7 ); G1 SS with long setae along proximal margins ( Fig. 7A, B View Figure 7 ). G2 SS base broadened tapering to long thin process that supports G2; G2 TA extremely short (TA/SS 0.12), broadened, tip small ( Fig. 7C View Figure 7 ).

Size: A small-size species, adult size range CW 20.1–26.5 mm.

Color in life: Dorsal carapace and appendages P2–P5 all dark brown; chelipeds (P1) red except for white tips ( Fig. 4A View Figure 4 ).

Etymology: The species is named for Bangem, the closest town to the type locality in Bakossi National Park. The species epithet is a noun in apposition.

Habitat: Buea bangem n. sp. is found in rivers and streams in the Bakossi National Park (NP), Southwest Cameroon ( Fig. 4B View Figure 4 ). This area covers a surface area of approximately 29,320 ha (293 km 2) that includes submontane and montane zones (between 900 m and 1,800 m asl).

Nomenclatural statement: A life science identifier (LSID) number was obtained for the new species: urn:lsid:zoobank. org:pub:399269F4-4FA2-4858-ADE0-C281CBF79278.