Afrithelphusa monodosa
Creators: name: Cumberlidge, Neil
name: Mvogo Ndongo, Pierre A.
name: Clark, Paul F.
name: Salieu, Sankoh
name: von Rintelen, Thomas
Publisher: name: Zenodo
Year: 2023
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Malacostraca
Decapoda
Deckeniidae
Afrithelphusa
Afrithelphusa monodosa

description: Afrithelphusa monodosa (Bott, 1959)
(Figures 1, 2 (d), 3(d), 4(c,g,k), 5(g,h,i,p), 6(k,l,p), 8; Tables 1–3)
The purple swamp crab
Globonautes monodosus Bott, 1959: 997, fig. 4a–b, 5, 6a–b; Monod 1977: 1209; 1980: 380; Cumberlidge 1987: 2212–2214, figs. 1a–d, 2a–b, tables 1, 2; 1996a: 692–693, figs. 1, 2, table 1; 1999: 224–225, figs. 46C, 47C, 48C, 49C, 50C, 51A, 52E, 53CC, 54–57, 62C, 68D.
Material examined
Type material. Holotype: Guinea: adult ♂ (CW 21.5 mm), Boké; 1 April 1947 (MNHN-B 5302).
Other material. Guinea. Adult ♂ (CW 24.3 mm), Sarabaya, Guinea (NMU 24.IV.2005), from burrow in cultivated land at Sarabaya, north of Kamsar, Boké Préfecture (10.754159°N, − 14.449672°W), 589 m ASL, coll. O. D. Bangoura, 24 April 2005; 6 specimens (NMU 25. IV.2005 A), from burrows in cultivated land at Sarabaya, north of Kamsar (10.754159°N, − 14.449672°W), 589 m ASL, coll. O. D. Bangoura and N. Cumberlidge, 25 April 2005; 5 specimens (NMU 25.IV.2005 B), from burrows in cultivated land at Sarabaya, north of Kamsar (10.754159°N, − 14.449672°W), 589 m ASL, coll. O. D. Bangoura and N. Cumberlidge, 25 April 2005; one specimen (NMU 27.IV.2005) from burrow in cultivated land at Sarabaya, north of Kamsar (10.754159°N, − 14.449672°W), 589 m ASL, coll. O. D. Bangoura and N. Cumberlidge, 27 April 2005.
Diagnosis
Carapace outline transversely oval, highly arched (CH /FW = 1.8); pterygostomial region of carapace branchiostegite smooth, lacking setal patches (Figure 4 (c)). Mandibular palp consisting of basis followed by two articles; terminal article (MPTA) bilobed, MPAL/ MPTA = 0.6 (Figure 4 (k); Table 3). Cheliped carpus texture roughened with granules, carinae (Figure 5 (l)); ambulatory legs P2–5 long, slender (ΣP2–5/CW = 6.2) (Figure 2 (d); Table 3). G1TA medium length (G1TA/G1SA = 0.4), slim, broadest proximally, curved distally, tapering to broad tip (Figure 6 (j)); Table 3); G1SA lacking raised rounded shoulder on external margin near G1TA-G1SA junction (Figure 6 (j, l)); DM narrow (Figure 6 (l)). G2TA medium length (G2TA/G2SA = 0.4), flagellum-like, ending in rounded tip (Figure 6 (k); Table 3). For detailed description see Bott (1959) and Cumberlidge (1987, 1996a).
Size
The adult size range is 21.0– 29.5 mm.
Colour
In living specimens the dorsal parts of the ambulatory legs are orange, the carapace is purple, and the thoracic sternum and undersides of the legs are cream.
Type locality
West Africa, Guinea, Boké.
Distribution
The western part of the Upper Guinea rainforest block of West Africa in Boké Prefecture, north-west Guinea (Figure 1).
Habitat
This species is known from two localities in Guinea that are both in the Northern Upper Guinea Ecoregion (FEOW 511). The new material was collected from marshy farmland near Sarabaya in southern Guinea.
Conservation
Afrithelphusa monodosa is considered an endangered species threatened with extinction under the IUCN Red List guidelines (Cumberlidge and Daniels 2020d). Fifty-eight years after the first specimens of A. monodosa were collected, several more were collected at Sarabaya, Guinea, from burrows dug into cultivated land in humid soil that contained a small amount of water at the bottom. Further population and distribution studies need to be carried out so that conservation options can be considered for the protection of this threatened species and its habitat (Mvogo Ndongo et al. 2022).
Remarks
This species was originally collected in 1947 and was known only from the holotype male from Boké, Guinea. A small number of specimens of A. monodosa were collected in 2005, including an adult male and the first adult female. The new specimens are conspecific with the types of A. monodosa, based on their key diagnostic characters (eg of the carapace, chelipeds, mandibles, pleon, G1, G2, and ambulatory legs) that all correspond closely to the types. This species was redescribed by Cumberlidge (1996a, 1996b, 1999). The carapace is the most highly arched (CH /FW = 1.83) of any species of Afrithelphusa and Globonautes from West Africa.
description: Published as part of Cumberlidge, Neil, Mvogo Ndongo, Pierre A., Clark, Paul F., Salieu, Sankoh & von Rintelen, Thomas, 2023, A revision of the West African freshwater crab genus Afrithelphusa Bott, 1969 (Brachyura: Deckeniidae: Deckeniinae) based on new morphological and genetic data, pp. 924-946 in Journal of Natural History 57 (13 - 16) on pages 941-943, DOI: 10.1080/00222933.2023.2216908, http://zenodo.org/record/8221731