Buea nlonako Mvogo Ndongo, von Rintelen, n. sp.
Creators: name: Mvogo Ndongo, Pierre A
name: von Rintelen, Thomas
name: Tomedi-Tabi Eyango, Minette
name: Cumberlidge, Neil
Publisher: name: Zenodo
Year: 2020
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Malacostraca
Decapoda
Potamonautidae
Buea
Buea nlonako

description: Buea nlonako Mvogo Ndongo, von Rintelen &
Cumberlidge n. sp.
(Figs. 2E, F, 3G, H, 4E, 5C, G, K, 6E, F, J, 7G–I, 8C, G)
Type material: Holotype adult male (CW 25.80 mm, CL 17.80 mm, CH 10.55 mm, FW 7.41 mm), Cameroon, Littoral region, Mt. Nlonako Ecological Reserve (04°54 ʹ 14.7 ʺ N, 09°58 ʹ 16.4 ʺ E), 1,500 m asl, 25 May 2018, coll. P. A. Mvogo Ndongo (ZMB Crust. 31786).
Paratypes: 3 adult males (CW 22.17 mm, CL 15.93 mm, CH 9.09 mm, FW 7.17 mm; CW 22.21 mm, CL 15.82 mm, CH 8.18 mm, FW 6.76 mm; CW 20.91 mm, CL 14.67 mm, CH 7.74 mm, FW 6.29 mm); 2 adult females (CW 30.10 mm, CL 21.78 mm, CH 11.04 mm, FW 8.43 mm; CW 25.12 mm, CL 17.13 mm, CH 9.58 mm, FW 7.17 mm), Littoral region, Mt. Nlonako Ecological Reserve (04°53 ʹ 33.04 ʺ N, 09°59 ʹ 14.0 ʺ E), 900 m asl, 26 May 2018, coll. P. A. Mvogo Ndongo (ZMB Crust. 31787).
Other material examined: 2 adult males (CW 23.31 mm, CL 16.44 mm, CH 8.59 mm, FW 7.60 mm; CW 24.00 mm, CL 17.24 mm, CH 9.30 mm, FW 7.30 mm); 3 adult females (CW 27.47 mm, CL 19.21 mm, CH 10.88 mm, FW 8.24 mm; CW 25.67 mm, CL 18.22 mm, CH 9.80 mm, FW 7.87 mm; CW 26.06 mm, CL 18.56 mm, CH 10.12 mm, FW 7.38 mm); subadult male (CW 16.76 mm, CL 12.60 mm, CH 6.39 mm, FW 5.82 mm), Littoral region, Mt. Nlonako Ecological Reserve (04°53 ʹ 33.4 ʺ N, 09°59 ʹ 14.0 ʺ E), 900 m asl, 26 May 2018, coll. P. A. Mvogo Ndongo (IFAS-012).
Diagnosis: Carapace medium height (CH/FW 1.28, N =12), anterior carapace surface completely smooth; cervical, urogastric, cardiac, branchial grooves distinct, very deep (Figs. 2E, 5G); postfrontal crest complete, meeting anterolateral margins (Fig. 5C); vertical (pleural) groove on carapace branchiostegite wall faint or absent; carapace branchiostegite lacking vertical (pleural groove) (Fig. 2F, 5C). Sternal sulcus S2/S3 horizontal, completely crossing sternum (Figs. 2F, 5K). Major cheliped dactylus stout, relatively straight, lined by small teeth, medium size tooth in middle, pollex of propodus with 3 large teeth proximally, followed by smaller teeth interspersed by 2 distinct teeth (Fig. 3G). Lower margin of cheliped merus lined by pointed teeth, distal tooth largest (sharp spine) (Figs. 2F, 6E, F). Terminal segment (TS) of mandibular palp bilobed, with small but distinct setae-fringed anterior lobe (0.1× TS length) (Fig. 8C). G1 TA broad, long, but not equal to SS length (TA/SS 0.70) (Figs. 7G, H); G2 TA extremely short (TA/SS 0.18) (Fig. 7I).
Description: Carapace ovoid, medium height (CH/FW 1.28, N = 12), width more than 3× FW (CW/FW 3.31, N = 12); carapace surface smooth, anterior corners of carapace each with
field of carinae; cervical, urogastric, cardiac, branchial grooves distinct, very deep (Figs. 2E, 5G); postfrontal crest distinct, complete, lateral ends meeting anterolateral margins (Figs. 2E, 5C, G); exorbital angle low, clearly distinct, intermediate, epibranchial teeth each reduced to small granule (Fig. 5C); anterolateral margin behind epibranchial tooth with small granules (Fig. 5C). Carapace branchiostegite with longitudinal suture dividing wall into 2 regions, lacking vertical (pleural) groove (Figs. 2F, 5C). Margin of sternum with setae; sternal sulcus S2/S3 horizontal, completely crossing sternum; S3/S4 incomplete, reduced to 2 small side notches (Figs. 2F, 5K); episternal sulci S4/E4, S5/E5, S6/E6 complete, S7/E7 missing (Figs. 2F, 5K).
Chelipeds of adult male greatly unequal (Figs. 2E, F, 3G, H). Fingers slim, elongated; movable finger (dactylus) stout, straight, lined by small teeth, medium size tooth in middle, pollex of propodus with 3 large teeth proximally, followed by smaller teeth interspersed by 2 distinct teeth (Fig. 3G). Minor cheliped dentition similar to major cheliped but smaller, enclosing oval interspace
when closed (Figs. 3H). Cheliped carpus with 2 large, unequal teeth, distal tooth largest, proximal tooth smallest (Figs. 6J). Medial inferior margin of cheliped merus with large distal tooth, lined by small pointed teeth proximally (Figs. 2F, 6E, F). Walking legs (pereiopods P2–P5) moderate length (not unusually elongated), posterior margins of propodi lined by small pointed teeth, dactyli tapering, each bearing rows of downward-pointing large sharp spines, tip with long spine (Figs. 2E, F).
Mandibular palp 2-segmented, terminal segment (TS) bilobed, with short but distinct setae-fringed anterior lobe (0.1× TS length) (Fig. 8C). Third maxillipeds filling entire buccal cavern, except for transversely oval efferent respiratory openings in superior lateral corners (Fig. 8G); ischium with distinct vertical sulcus; third maxilliped exopod either completely lacking flagellum, or with extremely reduced short process (Fig. 8G).
Male pleon triangular, sides not indented, telson (A7) rounded at distal margin (Figs. 2F, 5K). G1 TA long (TA/SS 0.70), proximal half straight, robust, distal half directed outward tapering evenly to pointed tip, G1 TA with long setae lining ventral margin (Figs. 7G, H). G2 SS robust at base, tapering to long thin rod, reaching middle of G1 TA. G2 TA extremely short (TA/SS 0.18), slender (Fig. 7I).
Size: A medium-size species, adult size range CW 20.9–30.1 mm.
Color in life: Dorsal carapace and appendages all dark brown; P1, chelipeds dark brown with white fingertips (Fig. 4E).
Type locality: Nlonako Wildlife Reserve, Nkongsamba, Littoral region, Cameroon.
Etymology: The new species is named for the Nlonako Wildlife Reserve. The species epithet is a noun in apposition.
Habitat: Buea nlonako n. sp. is known only from the Nlonako Wildlife Reserve, which includes Mt. Nlonako, which rises from 400 m asl on its southern side to 1,825 m at its peak (Fig. 4G). The reserve lies in the Littoral region of Cameroon, which is one of the most threatened tropical rainforest habitats in this part of Africa.
Nomenclatural statement: A life science identifier (LSID) number was obtained for the new species: urn:lsid:zoobank. org:pub:399269F4-4FA2-4858-ADE0-C281CBF79278.
description: Published as part of Mvogo Ndongo, Pierre A, von Rintelen, Thomas, Tomedi-Tabi Eyango, Minette & Cumberlidge, Neil, 2020, Morphological and molecular analyses reveal three new endemic species of the freshwater crab genus Buea Cumberlidge, Mvogo Ndongo, Clark & amp; Daniels, 2019 (Crustacea: Brachyura: Potamonautidae) from a rainforest biodiversity hotspot in Cameroon, Central Africa, pp. 288-300 in Journal of Crustacean Biology 40 (3) on pages 294-297, DOI: 10.1093/jcbiol/ruaa019, http://zenodo.org/record/15084901