Buea asylos ( Cumberlidge, 1993 ) Cumberlidge & Mvogo Ndongo & Clark & Daniels, 2019

Cumberlidge, Neil, Mvogo Ndongo, Pierre A., Clark, Paul F. & Daniels, Savel R., 2019, A new genus for the freshwater crab Potamonemus asylos Cumberlidgeı 1993 ı (Brachyura: Potamoidea: Potamonautidae) from Cameroonı Central Africaı with a key to the genera of the Potamonautinae, Journal of Natural History 53 (11), pp. 659-676 : 665-666

publication ID

https://doi.org/ 10.1080/00222933.2019.1583390

DOI

https://doi.org/10.5281/zenodo.3680412

persistent identifier

https://treatment.plazi.org/id/03BB87C0-1031-3927-438D-F8AEFC39F930

treatment provided by

Valdenar

scientific name

Buea asylos ( Cumberlidge, 1993 )
status

comb. nov.

Buea asylos ( Cumberlidge, 1993) comb. nov.

( Figures 1 View Figure 1 (a,b), 4(a), 5(a,b,g), 6(a,b), 7(a,d) and 8(a,d,g))

Type species. Potamonemus asylos Cumberlidge, 1993 , by present designation.

Potamonemus asylos Cumberlidge, 1993: 576 – 584 , figs 3, 4, 5a – b, 6a – c, 8a – b; tables 2, 3; Cumberlidge 1999: figs 40C, 41C,F, 42C,F, 43C,F, 44C, 53G, 54 – 57, 61E, 65F, table IX; Ng et al. 2008: 171; Cumberlidge 2011a: 78, 80, 82, 86, table 6.1; Cumberlidge 2011b: 190; Mvogo Ndongo et al. 2017b: 3, table 1; Daniels et al. 2015, table 1.

Material examined

Type material. Cameroon: Buea asylos ( Cumberlidge, 1993) comb. nov. adult ♂ holotype, CW 27.6, CL 18.3, CH 9.0, FW 7.5 mm, between Buea (4.153484°N, 9.299551°E) and GoogleMaps Kumba (4.638727°N, 9.441354°E), South-West Region, coll GoogleMaps . R.H.L. Disney, 1969 ( NHM 1994.587 donation from NMU 1969 /1991) . Paratypes, 3 ♀♀, CWs 25.4, 23.7, 18.7 mm, 3 ♂♂, CWs 22.3, 20.1, 19.8 mm, between Buea (4.153484°N, 9.299551°E) and GoogleMaps Kumba (4.638727°N, 9.441354°E), South-West Region, coll GoogleMaps . R.H.L. Disney, 1969 ( NHM 1994.588 591 ), DNA voucher specimens ( Daniels et al. 2015, table 1) . Adult ♂, CW 22.4, CL 15.8, CH 6.8, FW 6.9 mm, Buea (4.153484°N, 9.299551°E) Kumba area, South-West Region, coll GoogleMaps . R. H.L. Disney, 1969 ( NMU TRW 1969.22 ), specimen photographed here .

Other material examined. Adult ♀, CW 23.2, CL 17.2, CH 7.4, FW 7.4 mm, Buea (4.153484°N, 9.299551°E), Kumba area , South-West Region, coll GoogleMaps . R.H.L. Disney, 29 April 1969 ( NMU TRW 1969.13 a) . Adult ♂, CW 19.8, CL 14.5, CH 6.8, FW 6.9 mm, 3 subadult ♂♂, CWs 16.4, 15.6, 14.9 mm, subadult ♀, CW 15.3 mm, 9 juv ., Okia Stream, Kumba area , South-West Region, coll . R.H.L. Disney, 9 May 1969 ( NMU TRW 1969.27 ) . Adult ♂, CW 19.0 mm, 3 subadult ♂♂, CWs 18.4, 15.8, 12.6 mm, subadult ♀, CW 17.9 mm, 2 juv . , Okia Stream, Kumba area , South-West Region, coll. R.H.L. Disney, 27 March 1969 ( NMU TRW 1969.29 ) . Limbé (formerly Victoria), South-West Region , 2 ♂♂, CWs 21.3, 20.1 mm, coll . E . Fickenday, 6 November 1912, ‘ edible land crabs ’ ( ZIM K-3607) .

Diagnosis

Exorbital tooth absent where anterolateral margin meets lateral orbital margin ( Figures 1 View Figure 1 (a,b) and 4(a)); major cheliped dactylus broad, flattened, not arched ( Figures 1 View Figure 1 (b) and 5(a,b)); lower margin of cheliped merus with four large jagged pointed teeth ( Figures 1 View Figure 1 (b) and 6(a,b)); anterior corners of carapace surface smooth; carapace grooves shallow to absent ( Figures 1 View Figure 1 (a) and 4(a); Cumberlidge 1993, figs. 2a, 3a).

Description

Same as for the genus and for P. asylos comb. nov. (see Cumberlidge 1993, 1999).

Distribution

Buea asylos comb. nov. is endemic to the rainforest zone of south-western Cameroon between the towns of Kumba, Buea and Limbé ( Cumberlidge 1993, 1999).

Type locality

Between Buea and Kumba, south-western Cameroon.

Ecology

Buea asylos comb. nov. is restricted to the humid lowland and montane rainforests of south-western Cameroon in the area near Mount Cameroon (4095 m asl) that has an annual average rainfall of more than 5000 mm ( Mvogo Ndongo et al. 2017a, 2017b).

Remarks

Significant morphological differences between B. asylos comb. nov., P. mambilorum and P. sachsi were found in the G1, G2 and mandible ( Figures 7 View Figure 7 (a – f) and 8(a – c,g – i)) that are used here to define Buea gen. nov. Other noteworthy characters of B. asylos comb. nov. include those of the chelipeds and carapace of that set it apart from the two species of Potamonemus : the cheliped merus lower medial margin has large jagged teeth ( Figure 6 View Figure 6 (a,b)) (vs small granules in Potamonemus , Figure 6 View Figure 6 (c,f)), the cheliped carpus medial margin of B. asylos comb. nov. has a small but distinct pointed proximal tooth ( Figure 5 View Figure 5 (g)) (vs a small granule-sized tooth in Potamonemus , Figure 5 View Figure 5 (h,i)), the cheliped dactylus is distinctly broadened ( Figures 1 View Figure 1 (b) and 5 (a)) (vs distinctly slim or arched in Potamonemus , Figure 5 View Figure 5 (c,e)), and the carapace proportions of B. asylos comb. nov. are wider (CW/FW 3.35, vs 3.08 – 3.12), longer (CW/FW 2.32, vs 2.22 – 2.25), and higher (CW/FW 1.10, vs 0.96 – 1.07) than in Potamonemus .

Conservation status

The extinction risk status of B. asylos comb. nov. was assessed in 2008 using the International Union for the Conservation of Nature (IUCN) Red List protocols ( Cumberlidge 2008a) as Data Deficient (DD) in view of the lack of information on its extent of occurrence (EOO), ecological requirements, population size, population trends and long-term threats ( Cumberlidge 1993, 2011a, 2011b; Cumberlidge et al. 2009; IUCN 2012). The three locations available in this study give a recalculated EOO of 142 km 2, and an area of occupancy (AOO) of 12 km 2, using GeoCAT (http://geocat.kew.org; Bachman et al. 2011), but these are still probably underestimates given the paucity of the locality data (but if taken alone would point to a Red List threatened category). The extinction risk status of P. mambilorum (seven locations, EOO 43,291 km 2; Cumberlidge 2008b) and P. sachsi (four locations, EOO 24,219 km 2; Cumberlidge 2008c) were assessed in 2008 ( Cumberlidge 2008b, 2008c) as Least Concern (LC) and Vulnerable (VU), respectively, ( Cumberlidge 1993, 2011a, 2011b; Cumberlidge et al. 2009; IUCN 2012). Although the recalculations of the EOO and the AOO for these three species do not in themselves warrant a reassessment of their extinction risk, there is reason to believe that the threat status of these species may have intensified since the last assessment. For example, recent field work in the wetland ecosystems of the South-West and Littoral regions of Cameroon by the second author indicates that these habitats are being impacted by deforestation and by intensive agricultural practices that are severely altering the flow patterns of small streams and impacting the aquatic biodiversity ( Mvogo Ndongo et al. 2017a, 2017b, 2017c, 2018). Awareness of these current threats to the habitats of B. asylos comb. nov., P. mambilorum and P. sachsi means that each of these taxa is likely to be reassigned to a more threatened category once new IUCN Red List extinction risk assessments have been carried out. There is a need for further field research specifically aimed at gathering the data needed for an extinction risk assessment of these littleknown endemic species from this understudied biodiversity hotspot.

R

Departamento de Geologia, Universidad de Chile

ZIM

ZIM Culture Collection of Industrial Microorganisms

Kingdom

Animalia

Phylum

Arthropoda

Class

Malacostraca

Order

Decapoda

Family

Potamonautidae

Genus

Buea

Loc

Buea asylos ( Cumberlidge, 1993 )

Cumberlidge, Neil, Mvogo Ndongo, Pierre A., Clark, Paul F. & Daniels, Savel R. 2019
2019
Loc

Potamonemus asylos Cumberlidge, 1993: 576 – 584

Mvogo Ndongo PA & Schubart CD & von Rintelen T & Tamesse JL & Cumberlidge N 2017: 3
Cumberlidge N 2011: 78
Cumberlidge N 2011: 190
Ng PKL & Guinot D & Davie P 2008: 171
Cumberlidge N 1993: 584
1993