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).