Afrithelphusa monodosa (Bott, 1959)

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, Journal of Natural History 57 (13 - 16), pp. 924-946 : 941-943

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.

Figures

Figure 1. Distribution map of West Africa showing the known localities of all Afrithelphusa Bott, 1969 species in Guinea and Sierra Leone. Afrithelphusa afzelii (Colosi, 1924) (black triangle, not shown to scale); A. leonensis (Cumberlidge, 1987) (black circles, not shown to scale); A. monodosa (Bott, 1959) (black squares, not shown to scale); A. gerhildae Bott, 1969 (black diamond, not shown to scale). For exact localities see text. Scale bar = 111 km.

Figure 2. Afrithelphusa afzelii (Colosi 1924), adult ♂, CW 25.0 mm, ZMB Crust. 34,607, from Moyamba District, Sierra Leone: a, whole animal, dorsal view. Afrithelphusa gerhildae Bott, 1969, adult ♂ CW 22.5 mm, SMF 2619a, Le Voile de la Mariée, Kindia, Guinea: b, whole animal, dorsal view. Afrithelphusa leonensis (Cumberlidge, 1987), adult ♂, CW 26.4 mm, ZMB Crust. 34,606, from Guma Lake, Sugar Loaf Mountain, Sierra Leone: c, whole animal, dorsal view. Afrithelphusa monodosa (Bott, 1969), adult ♂, CW 24.3 mm, NMU 24.IV.2005, Sarabaya, Guinea: d, whole animal, dorsal view. Photographs a, c by PAMN; b by Michael Türkay; d by N. Cumberlidge and M. Lorenz. Scale bar: a = 17.2 mm; b = 15.5 mm; c = 18.9 mm; d = 15.7 mm. CW = carapace width, ZMB = Museum für Naturkunde, Berlin, Germany, SMF = Senckenberg Museum, Frankfurt, Germany, NMU = Northern Michigan University,USA,PAMN = Pierre Armand Mvogo Ndongo.

Figure 4. Afrithelphusa afzelii (Colosi 1924), adult ♂ CW 25.0 mm, ZMB Crust. 34,607, from Moyamba District, Sierra Leone: a, carapace, frontal view; d, thoracic sternum, h, mandible frontal view. Afrithelphusa gerhildae Bott, 1969, adult ♂ CW 22.5 mm, SMF 2619a, Le Voile de la Mariée, Kindia, Guinea: e, thoracic sternum, i, mandible frontal view (Cumberlidge 1999, fig. 48A). Afrithelphusa leonensis (Cumberlidge, 1987), adult ♂, CW 26.4 mm, ZMB Crust. 34,606, from Guma Lake, Sugar Loaf Mountain, Sierra Leone: b, carapace, frontal view; f, thoracic sternum, j, mandible frontal view. Afrithelphusa monodosa (Bott, 1969), adult ♂, CW 24.3 mm, NMU 24.IV.2005, Sarabaya, Guinea: c, carapace,frontal view; g, thoracic sternum, k, mandible, frontal view. Photographs a, c by P. A. Mvogo Ndongo; d by Neil Cumberlidge and Margaret Lorenz; e by Michael Türkay. Scale bar: a = 8.9 mm; b = 9.6 mm; c = 11.6 mm; d–g = 8.0 mm; h–k = 3.1 mm. CW = carapace width, ZMB = Museum für Naturkunde, Berlin, Germany, NMU = Northern Michigan University, USA.

Figure 5. Afrithelphusa afzelii (Colosi 1924), adult ♂ CW 25.0 mm, ZMB 34607, from Moyamba District, Sierra Leone: a, right cheliped, frontal view;b, left cheliped, frontal view;i, right cheliped carpus superior view; m, right cheliped merus superior view. Afrithelphusa gerhildae Bott, 1969, adult ♂ CW 22.5 mm, SMF 2619a, Le Voile de la Mariée, Kindia, Guinea: c, right cheliped, frontal view (Cumberlidge 1999, fig. 50A); d, left cheliped, frontal view (Cumberlidge 1999, fig. 50A); j, right cheliped carpus superior view; n, right cheliped merus superior view. Afrithelphusa leonensis (Cumberlidge, 1987), adult ♂, CW 26.4 mm, ZMB Crust. 34,606, from Guma Lake, Sugar Loaf Mountain, Sierra Leone: e, right cheliped, frontal view; f, left cheliped, frontal view; k, right cheliped carpus superior view; o, right cheliped merus superior view. Afrithelphusa monodosa (Bott, 1969), adult ♂, CW 24.3 mm, NMU 24.IV.2005, Sarabaya, Guinea: g, right cheliped, frontal view; h, left cheliped, frontal view; l, right cheliped carpus superior view; p, right cheliped merus superior view. Photographs a, b, e, f, i, k, m, o by P. A. Mvogo Ndongo; g, h, l, p by Neil Cumberlidge and Margaret Lorenz; j, n by Michael Türkay. Scale bar: a–h = 11.2 mm; i–p = 5.6 mm. CW = carapace width, ZMB = Museum für Naturkunde, Berlin, Germany, SMF = Senckenberg Museum, Frankfurt, Germany, NMU = Northern Michigan University, USA.

Figure 6. Afrithelphusa afzelii (Colosi 1924), adult ♂ CW 29.5 mm, SMNH 168, Sierra Leone: a, G1 ventral view; b, G2 ventral view; c, G1 dorsal view; m, third maxilliped, frontal view. Afrithelphusa gerhildae Bott, 1969, adult ♂ CW 22.5 mm, SMF 2619a, Le Voile de la Mariée, Kindia, Guinea: d, G1 ventral view; e, G2 ventral view (Cumberlidge 1999, fig. 53AA); f, G1 dorsal view (Cumberlidge 1999, fig. 52B); n, third maxilliped, frontal view (Cumberlidge 1999, fig. 49A). Afrithelphusa leonensis (Cumberlidge, 1987), adult ♂, CW 26.4 mm, ZMB Crust. 34,606, from Guma Lake, Sugar Loaf Mountain, Sierra Leone: g, G1 ventral view; h, G2 ventral view; i, G1 dorsal view; o, third maxilliped, frontal view.Afrithelphusa monodosa (Bott, 1969), adult ♂, CW 24.3 mm, NMU 24.IV.2005, Sarabaya, Guinea: j, G1 ventral view; k, G2 ventral view; l, G1 dorsal view; p, third maxilliped,frontal view. Photographs a–c, g–i, m, o by P. A. Mvogo Ndongo; j–l, p by Neil Cumberlidge and Margaret Lorenz;d by Michael Türkay.Scale bar:a, c, d, f, g, i, j, l = 10.0 mm; b, e, h, k = 5.8 mm; m–p = 2.4 mm. CW = carapace width, SMNH = Swedish Museum of Natural History, Stockholm,Sweden,G1 = gonopod 1, G2 = gonopod 2, ZMB = Museum für Naturkunde,Berlin,Germany, SMF = Senckenberg Museum, Frankfurt, Germany, NMU = Northern Michigan University, USA.