Afrithelphusa gerhildae Bott, 1969

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 : 938-939

Afrithelphusa gerhildae Bott, 1969

( Figures 1 , 2 (b), 3(b), 4(e,i), 5(c,d,j,n), 6(d,e,f,n), 8; Tables 1–3 )

Gerhilda̍s freshwater crab

Afrithelphusa gerhildae Bott, 1969: 360 ; 1970: 26–27, pl. 2, fig. 9–11, pl. 26, fig. 9; Monod 1977: 1210; 1980: 380; Cumberlidge 1996a: 688–690, table 1; 1999: 220–223, fig. 46A, 47A, 48A, 49A, 50A, 518, 528, 53AA, 54–57, 62A, 68B, table IX, pl 1.

Material examined

Type material. Holotype: Guinea: adult ♂ (CW 22.5 mm), Le Voile de la Mariée , Kindia, near Conakry (9.982013°N, − 12.795237°W), 123 m ASL, coll. Marchal, 8 July 1957 ( SMF 2619 a) . Paratype, adult ♀ ( CW 22 mm), Le Voile de la Mariée , Kindia, near Conakry (9.982013°N, − 12.795237°W), 123 m ASL, coll. Marchal, 8 July 1957 ( SMF 2619 b) .

Diagnosis

Carapace outline transversely oval, highly arched ( CH /FW = 1.5); pterygostomial region of carapace branchiostegite with patches of dense short setae ( Cumberlidge 1999, pl. 1). Mandibular palp consisting of basis followed by two articles; terminal article (MPTA) bilobed (MPAL/MPTA = 0.7) ( Figure 4 (i); Table 3 ; Cumberlidge 1999, fig. 48A). Cheliped carpus smooth-textured ( Figure 5 (j)); ambulatory legs P2–5 medium length ( Figure 1 (b); Table 3 ; Cumberlidge 1999, pl. 1). G1TA medium length (G1TA/G1SA = 0.4), slim, broadest proximally, distal half curving outward; Cumberlidge 1999, fig. 52A); G1SA lacking raised rounded shoulder on external margin near G1TA-G1SA junction ( Figure 6 (d,f)); DM narrow (( Figure 6 (f)), Cumberlidge 1999, fig. 52AA). G2TA medium length (G2TA/G2SA = 0.5), flagellum-like, with distinct distal curve, ending in rounded tip ( Figure 6 (e); Table 3 ; Cumberlidge 1999, fig. 53AA). For full description see Bott (1959, 1969, 1970); Monod (1977); Cumberlidge (1987, 1991, 1996a, 1996b, 1999).

Size

The adult size range begins at CW 22 mm.

Colour

Unknown in life. Preserved specimens are uniformly pale brown.

Distribution

The western part of the Upper Guinea rainforest zone in Guinea, West Africa ( Figure 1 ).

Type locality

West Africa , Guinea, Le Voile de la Mariée, Kindia, near Conakry (9.982013°N, − 12.795237°W) .

Habitat

This species is known from a single locality in the Northern Upper Guinea Ecoregion ( FEOW 511 ), and was collected from a pool at the bottom of an 80 m waterfall in an area surrounded by rainforest that includes giant bamboos .

Conservation

Afrithelphusa gerhildae is likely a threatened species in danger of extinction, although it is currently considered under the IUCN Red List guidelines to be a Data Deficient species because there is little or no information available on its population size and trends, habitat, distributional range, or threat ( Cumberlidge and Daniels 2020a; Mvogo Ndongo et al. 2022).

Remarks

The medium-length flagellum of the G2TA of the male holotype of A. gerhildae (( Figure 6 (e)); Cumberlidge 1999, fig. 52AA) is similar in length to that of A. monodosa , A. leonensis and A. afzelii (( Figure 6 (b,h,k)); Table 3 ) and is strikingly longer than the short stub-like G2TA of G. macropus ( Table 3 ). Bott (1959) listed a male from Le Voile de la Mariée, Guinea (CW 22.5 mm, SMF 2619a) under G. macropus and used this specimen for his illustrations of the mandible and gonopods (Bott 1959, figs. 1–3), rather than basing his illustrations on the holotype of G. macropus . This would explain why the text and the figure of the G 2 in Bott (1959, fig. 3) shows a medium-length flagellum-like G2TA (as in A. gerhildae (Figure (6e)), rather than a short stub-like G2TA (and not a flagellum) characteristic of G. macropus ( Cumberlidge 1999, fig. 53Z; Table 3 ). The specimen (SMF 2619a) used by Bott (1959) to illustrate G. macropus was later transferred by Bott (1969) to Afrithelphusa , when he established A. gerhildae . Afrithelphusa gerhildae was later redescribed by Cumberlidge (1996a, 1996b, 1999).

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.