Afroceto plana, Lyle & Haddad, 2010

Lyle, Robin & Haddad, Charles R., 2010, A revision of the tracheline sac spider genus Cetonana Strand, 1929 in the Afrotropical Region, with descriptions of two new genera (Araneae Corinnidae), African Invertebrates 51 (2), pp. 321-321 : 359-363

Afroceto plana sp. n.

Figs 16, 17 , 81–101

Etymology: From Latin planus (flat); refers to the flat tibial apophysis of the male.

Diagnosis: The male of this species is closely related to A. martini but can be recognised by the flat retrolateral tibial apophysis with a single dorsally directed tooth-like excrescence, the more compact tegulum and cymbium, and the embolus that is directed distally after emerging from beneath the tegulum, with the tip close to the retrolateral cymbial margin ( Figs 97, 98 ). The female can be recognised by the curved copulatory ducts, with ST II extending beyond the anterior margins of the lateral epigynal ridges ( Figs 100, 101 ); in A. martini the copulatory ducts are distinctly coiled and ST II do not reach the anterior margin of the lateral epigynal ridges ( Figs 36, 37 ).

Description:

Male.

Measurements: CL 2.10–2.80, CW 1.83–2.50, AL 2.30–3.20, AW 1.53–2.20, TL 4.40– 6.10, FL 0.18–0.28, SL 1.23–1.58, SW 1.08–1.45, AME–AME 0.13, AME–ALE 0.08, ALE–ALE 0.53, PME–PME 0.20, PME–PLE 0.20, PLE–PLE 0.83. Length of leg segments (sequence from femur to tarsus, and total): I 2.43+1.18+2.05+1.70+1.08=8.44; II 2.15+1.24+1.80+1.63+0.98=7.80; III 1.53+0.85+1.10+1.48+0.73=5.69; IV 2.18+0.98+ 1.93+2.33+0.73=8.15.

Carapace brown to dark brown, slightly paler posterior to fovea ( Fig. 16 ); first two thirds of carapace slightly raised with highest point near one third of carapace length; last third with relatively steep decline; surface slightly granular, covered in short fine setae; fovea short, distinct, slightly thickened, at two thirds CL. Ocular region dark brown with black rings around eyes; AER slightly procurved, AME larger than ALE; clypeus height equal to 0.5 AME diameter; AME separated by slightly less than 0.5 their diameter; AME separated from ALE by 0.3 AME diameter; PER slightly recurved, PLE larger than PME; PME separated by 1.5 times their diameter; PME separated from PLE by distance equal to PME diameter ( Fig. 81 ). Chelicerae dark brown, paler near base; anterior surface covered in long, dark setae; fangs bright orange, darker at fang base; three promarginal teeth, median and proximal teeth subequal in size, distal tooth smallest; two retromarginal teeth, distal tooth slightly larger than proximal tooth. Sternum pale brown to yellow, covered in fine long setae throughout ( Fig. 82 ). Abdomen cream to light brown dorsally, with dark grey ventral line, either branched into a chevron or unbranched; abdomen broader anteriorly, tapering posteriorly; two pairs of grey sigilla, one pair anterior and other posterior to midpoint of abdomen; venter cream. Legs I to IV uniform pale yellow to light brown, with incomplete grey bands on femora to metatarsi; relatively dense scopulae ventrally on metatarsi and tarsi, remaining leg segments covered in fine, pale setae; anterior femora with two incomplete distal bands, tibiae with incomplete distal and proximal bands, metatarsi with incomplete distal and proximal band; posterior pairs of legs with similar band arrangement, with exception of femora, with one incomplete distal band; leg spines and cusps present. Leg spination: femora: I pl 1, II pl 1, III pl 1 rl 1, IV pl 1 rl 1; patellae spineless; tibiae: I plv 7–10 rlv 0–4 vt 1 cusps, II plv 4–9 rlv 0–4 cusps, III pl 1 rl 1 plv 1 vt 2; metatarsi: I plv 10–14 rlv 8–11 vt 2 cusps, II plv 13 rlv 9 vt 2 cusps, III pl 1 rl 1 plv 2 rlv 1, IV pl 1 rl 1 plv 2; tarsi: I plv 4–10 rlv 3–8 cusps, II plv 4–8 rlv 2–5 cusps ( Figs 83–86 , 96 ). Palp yellow­brown; embolus originating prolaterally, curving beneath tegulum, emerging distally; distal section of embolus directed distally, tip fist-like, close to retrolateral margin of cymbium ( Figs 87 , 97 ); cymbium with two short ventral spines, located prolaterally and retrolaterally near distal end of cymbium ( Fig. 97 ); retrolateral tibial apophysis prominent, flattened, broad, with sharp, dorsally directed tooth-like excrescence; patellar apophysis sharp, slightly curved ( Fig. 98 ).

Female.

Measurements: CL 2.00–2.40, CW 1.78–2.08, AL 2.40–4.00, AW 1.85–2.60, TL 5.00– 6.30, FL 0.13–0.28, SL 1.33–1.43, SW 1.05–1.16, AME–AME 0.08, AME–ALE 0.05, ALE–ALE 0.45, PME–PME 0.23, PME–PLE 0.10, PLE–PLE 0.58. Length of leg segments (sequence from femur to tarsus, and total): I 2.05+0.95+1.55+1.40+0.95=6.90; II 1.83+0.88+1.38+1.35+0.88=6.32; III 1.38+0.73+0.95+1.25+0.48=4.79; IV 2.05+0.85+ 1.73+2.00+0.65=7.28.

Carapace orange to dark brown, paler posterior to midpoint ( Fig. 17 ); first two thirds of carapace raised, with highest point at one third of carapace length, posterior third declining steeply; surface smooth, covered in short, fine setae; fovea short, distinct, slightly thickened, at two­thirds CL. Ocular region light brown with dark brown rings around eyes; AER slightly recurved, AME larger than ALE; clypeus height equal to 0.8 AME diameter; AME separated by 0.6 their diameter; ALE separated from AME by 0.8 AME diameter; PER slightly recurved, PLE larger than PME; PME separated from PLE by distance equal to 1.5 their diameter; PME separated by distance equal to PME diameter. Chelicerae light brown, slightly darker at fang base; anterior surface of chelicerae with scattered setae ( Fig. 88 ); fangs orange; three promarginal teeth, proximal tooth largest, distal tooth smallest; two retromarginal teeth, proximal tooth largest. Sternum pale yellow, brown towards borders; surface covered in long, fine setae. Abdomen pale yellow to cream dorsally, with light grey lateral stripe; abdomen broader anteriorly, tapering posteriorly; one pair of pale grey sigilla anterior to midpoint of abdomen; fine setae scattered throughout dorsum; venter cream. Legs I to IV uniform light brown to pale yellow; erect setae on anterior legs, alongside cusps on tibiae, metatarsi and tarsi; dense scopulae ventrally on anterior metatarsi and tarsi ( Figs 90–92 ). Leg spination: femora: I pl 1, II pl 1, III pl 1 rl 1, IV pl 1 rl 1; patellae spineless; tibiae: I plv 9–13 rlv 4–7 cusps, II plv 2–8 rlv 3–4 cusps, III pl 1 rl 1 rlv 1, IV pl 1 rl 2 plv 1 vt 2; metatarsi: I plv 14–16 rlv 9–10 cusps, II plv 11–12 rlv 8–9 cusps, III pl 1 rl 1 rlv 1, IV pl 1 rl 1 plv 1; tarsi: I plv 6 rlv 4–6 cusps, II plv 3–4 rlv 1–3 cusps ( Figs 89, 91–93 , 99 ). Genital area sclerotised; lateral epigynal ridges comma­shaped, copulatory openings directed anteriorly; epigyne without mating plugs ( Fig. 94 ) or with plugs ( Fig. 95 ); copulatory ducts broad, curved, leading to small anterior ST II extending beyond anterior margin of lateral ridges ( Figs 100, 101 ); narrow duct leading posteriorly from ST II to medially placed globular ST I in posterior half of epigyne ( Fig. 101 ).

Holotype: ♂ SOUTH AFRICA: KwaZulu-Natal: Ndumo Game Reserve, Crocodile Farm , 26°54.426'S: 32°19.185'E, 19.i.2002, C. Haddad, leaf litter under fig tree ( NCA, 2002/385).

Allotype: ♀ SOUTH AFRICA: KwaZulu-Natal: Ndumo Game Reserve, W shore of Nyamiti Pan , 26°53.767'S: 32°16.557'E, 3.vii.2003, C. Haddad, under Acacia xanthophloea bark ( NCA, 2006/1488).

Paratypes: SOUTH AFRICA: KwaZulu-Natal: 5♂ Ndumo Game Reserve, Start of game count transect 8, 26°50.183'S: 32°13.135'E, 2.vii.2003, C. Haddad, under bark of fever tree ( NCA, 2006/1493) . Western Cape: 1♂ 4♀ 1 juv. De Hoop Nat. Res., Potberg , 34°22.487'S: 20°31.980'E, 6.iv.2004, C. Haddad, leaf litter ( NCA, 2006/1505) .

Other material examined: MALAWI: 1♀ Viphya Mountains, Chikangawa , 11°50'S: 33°48'E, ix–x.1977, R. Jocqué, old pine plantation ( MRAC, 153548) . SOUTH AFRICA: Free State: 1♂ Bloemfontein district , “Hopefield” farm, 28°54'S: 26°14'E, 1.xii.2001, C. Haddad, under Bluegum bark ( NCA, 2006/1478) ; 1♂ 1 juv. Sandveld Nat. Res. , 27°41'S: 25°43'E, 25 x.2003, C. Haddad, in chimney of Odontotermes termite mound ( NCA, 2002/507). KwaZulu-Natal : 1♀ Ndumo Game Reserve, Crocodile Farm , 26°54.426'S: 32°19.185'E, 28.vi.2003, C. Haddad, active search ( NCA, 2006/1494) ; 2♀ same locality, Crocodile Farm , 26°54.426'S: 32°19.185'E, 8 xii.2000, C. Haddad, fever tree, active search ( NCA, 2006/1506) ; 2♂ same locality, E shore of Shokwe Pan , 26°52.516'S: 32°12.407'E, 21.vi.2006, C. Haddad, under logs ( NCA, 2006/1238) ; 3♂ same data ( NCA, 2006/1244) ; 1♂ same locality, near Nyamiti Bird Hide, Pongola R. floodplain, Ezikebheni , 26°53.362'S: 32°18.892'E, 9.ii.2005, C. Haddad, leaf litter, floodplain ( NCA, 2005/40) ; 16♂ same locality, start of game count transect 8, 26°50.183'S: 32°13.135'E, 2.vii.2003, C. Haddad, under fever tree bark ( NCA, 2006/1484) ; 8♀ same data ( NCA, 2006/1485) ; 6♀ same locality, start of game count transect 8, 26°50.183'S: 32°13.135'E, 2.vii.2004, C. Haddad, Ficus bark ( NCA, 2006/1492) ; 3♂ same locality, W shore of Nyamiti Pan , 26°53.767'S: 32°16.557'E, 3.vii.2003, C. Haddad, under A. xanthophloea bark ( NCA, 2006/1487). Limpopo : 1♀ Tuinplaas, Springbokvlakte, Settlers Lodge , 7.v.2002, M. van Jaarsveld, aru 5731 grass, pitfall trap ( NCA, 2003/332) ; 1♀ same locality, 7.v.2002, M. van Jaarsveld, aru 5730 grass, pitfall trap ( NCA, 2003/333) ; 1♀ same locality, 7.v.2002, M. van Jaarsveld, aru 5734 grass, pitfall trap ( NCA, 2003/334) .

Distribution: Recorded from the eastern, central and southern parts of South Africa, with a single specimen collected in Malawi ( Fig. 105 ).

Figures

Figs 1–22. General appearance of Afroceto gen. n. species: A. martini (Simon, 1897) comb. n. female (1) and male (2); A. arca sp. n. female (3) and male (4); A. bulla sp. n. female (5); A. bisulca male (6); A. capensis sp. n. female (7) and male (8); A. coenosa (Simon, 1897) comb. n. female (9); A. corcula sp. n. female (10); A. croeseri sp. n. female (11) and male (12); A. flabella sp. n. male (13) and female (14); A. gracilis sp. n. male (15); A. plana sp. n. male (16) and female (17); A. porrecta sp. n. male (18); A. rotunda sp. n. male (19) and female (20); A. spicula sp. n. male (21) and female (22).

Figs 81–95. Scanning electron micrographs of Afroceto plana sp. n. male (81–93) and female (94, 95): (81) eye arrangement, dorsal view; (82) sternum; (83) individual cusp on tibia I; (84, 91) tibia I, ventral cusps; (85, 92) metatarsus I, ventral cusps and scopulate setae; (86, 93) tarsus I, cusps and scopulate setae; (87) left palp, ventral view; (88) fangs, ventral view; (89) individual cusp on metatarsus I; (90) detail of scopulate seta on metatarsus I; (94) epigyne, ventral view, without plugs; (95) epigyne, ventral view, with plugs.

Figs 96–101.Afroceto plana sp. n.male (96–98) and female (99–101):(96, 99) schematic representation of cusp arrangement legs I and II; (97) left palp, ventral view; (98) left palp, retrolateral view; (100) epigyne, ventral view; (101) vulva, dorsal view. Scale bars (97, 98, 100, 101) = 0.1 mm.

Figs 35–41. Afroceto martini (Simon,1897) comb.n.female (35–37) and male (38–41):(35, 38) schematic representation of cusp arrangement onlegs I and II; (36) epigyne,ventral view; (37) vulva,dorsal view; (39) left palp, ventral view; (40) left palp, retrolateral view; (41) left palp, variation in retrolateral tibial apophysis, retrolateral view. Scale bars (36, 37, 39–41) = 0.1 mm.

Fig. 105. Distribution of Afroceto plana sp. n. and A. porrecta sp. n. in southern Africa.