Afroceto arca, 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 : 339-343

Afroceto arca sp. n.

Figs 3, 4 , 43–49

Etymology: From Latin arcus (arch), referring to the arch­like structure of the anterior epigynal hood.

Diagnosis: This species can be recognised by the arch­shaped anterior hood of the epigyne and the two bulbous spermathecae that flank the copulatory openings ( Fig. 43 ). The males can be recognised by the curve of the embolus and the rounded tip of the subtriangular retrolateral tibial apophysis ( Figs 47, 49 ). The sperm duct of this species is U­shaped and narrows towards the tip of embolus, either branching or not. The two variations of the male palp had largely overlapping ranges. However, no variation in female epigyne structure was observed in these populations, suggesting that these specimens are all conspecific.

Description:

Female. Measurements: CL 1.98–3.00, CW 1.70–2.50, AL 2.25–4.60, AW 1.45–2.90, TL

4.10–8.10, FL 0.10–0.15, SL 1.13–1.70, SW 0.98–1.38, AME–AME 0.13, AME–ALE 0.05, ALE–ALE 0.55, PME–PME 0.18, PME–PLE 0.20, PLE–PLE 0.88. Length of leg segments (sequence from femur to tarsus, and total): I 2.40+1.13+1.88+1.55+1.15=8.21; II 2.20+1.18+1.70+1.48+1.18=7.74; III 1.53+0.90+1.13+1.40+0.58=5.54; IV 2.28+1.03+ 1.85+2.15+0.65=7.96.

Carapace orange to dark brown ( Fig. 3 ); slightly raised to midpoint, with relatively gradual decline posteriorly; surface smooth, covered in short fine setae; fovea short, thickened, distinct, at ⅔ CL. Ocular region dark orange to brown with dark brown rings around eyes; AER very slightly recurved, nearly straight, AME slightly larger than ALE; clypeus height equal to AME diameter; AME separated by distance approximately equal to their diameter; AME separated from ALE by 0.25 AME diameter; PER slightly recurved, PLE slightly larger than PME; PME separated by distance approximately equal to their diameter; PME separated from PLE by distance slightly larger than PME diameter. Chelicerae orange, dark brown towards border; dark long setae scattered on the anterior surface; fangs bright orange; three promarginal teeth, median tooth largest, distal tooth smallest; two retromarginal teeth, distal tooth slightly larger. Sternum orange, brown towards border; surface with long brown setae and short, light fine setae scattered throughout. Abdomen cream to pale yellow dorsally with grey chevron markings, with darkened median line and light grey transverse branches up to midpoint; abdomen broader anteriorly, tapering posteriorly; venter cream. Legs I to IV uniform orange; tibiae, metatarsi and tarsi with dense ventral scopulae; remaining leg segments covered with fine, less dense setae. Anterior legs slightly more robust than posterior. Leg spination: femora: I pl 3; patellae spineless; tibiae: III pl 1 vt 1, IV plv 2 vt 1; metatarsi: III pl 1 rl 1. Genitalia weakly sclerotised; epigynal anterior hood arched-shaped; copulatory openings situated mediolaterally, flanked by ST I and ST II; ST II large, globular, extending to approximately midpoint of epigyne; ST I small and globular, partially hidden by copulatory openings; ST I linked by narrow transverse duct ( Figs 43, 44 ).

Male.

Measurements (eye and leg measurements taken from second largest specimen): CL 1.76–3.70, CW 1.45–3.00, AL 1.90–3.90, AW 1.30–2.70, TL 3.70–7.60, FL 0.10– 0.35, SL 1.10–1.75, SW 0.90–1.75, AME–AME 0.15, AME–ALE 0.10, ALE–ALE 0.73, PME–PME 0.25, PME–PLE 0.28, PLE–PLE 1.13. Length of leg segments (sequence from femur to tarsus, and total): I 3.00+1.50+2.70+1.80+1.30=10.30; II 2.60+1.35+2.33+1.65+1.08=9.01; III 1.70+1.05+1.10+1.58+0.58=6.01; IV 2.40+1.15+ 2.03+2.30+0.73=8.61.

Carapace orange to brown ( Fig. 4 ); first third of carapace slightly raised with gradual decline in last two thirds; surface covered in short, fine setae; fovea short, thickened, distinct, at two thirds CL. Ocular region dark orange to brown with dark brown to black rings around eyes; AER very slightly procurved, AME slightly larger than ALE; AME separated by distance approximately equal to their diameter; AME separated from ALE by distance equal to half AME diameter; PER slightly recurved, PLE slightly larger than PME; PME separated by distance equal to 1.2 diameter; PME separated from PLE by distance equal to PLE diameter. Chelicerae orange to dark brown near fang base; anterior surface with scattered black setae; fangs orange at tip, dark brown at fang base; three promarginal teeth, median tooth largest, distal and proximal teeth subequal in size; two retromarginal teeth, distal tooth largest. Sternum orange, brown towards border; surface with scattered long brown and short pale setae. Abdomen cream dorsally with orange scutum covering entire dorsum; dorsum with pale brown chevron with thickened median line and pale brown transverse branches and dark grey lines laterally; abdomen broader anteriorly, tapering posteriorly; surface smooth with fine short dark setae throughout; venter cream. Legs I to IV uniform orange to brown; anterior legs slightly more robust than posterior legs; tibiae, metatarsi and tarsi with dense scopulae ventrally, remaining leg segments covered in fine, short dark setae. Leg spination: femora: I pl 2–3, II pl 3–4; patellae spineless; tibiae: I plv 15 vt 1 cusps, II plv 8 rlv 2 vt 2 cusps, III pl 1 plv 2–4 vt 1, IV plv 2 vt 2; metatarsi: I plv 3–12 cusps, II plv 2–8 cusps, III plv 2 rlv 1, IV rl 1 plv 2 rlv 1; tarsi: I plv 6 rlv 9 cusps, II plv 5–7 rlv 7 cusps ( Fig. 45 ). Palp yellow­brown; embolus curved, distally located on tegulum, slightly coiled; sperm ducts U­shaped, unbranched ( Fig. 46 ) or branched ( Fig. 48 ) distally near embolus base; tibial apophysis prominent, subtriangular with rounded point ( Figs 47, 49 ).

Holotype: ♀ SOUTH AFRICA: Gauteng: Knoppieslaagte [25.93°S: 28.05°E], 13.ii.1980, D. Uys, pitfalls ( NCA 84 /605).

Allotype: ♂ LESOTHO: Mohale Dam , Island 2, 29°25.396'S: 28°05.903'E, 14 xii.2003, C. Haddad, under rocks on hillside ( NCA, 2006/1515).

Paratypes: SOUTH AFRICA: Free State: 2♀ Bloemfontein district , “Deelhoek” farm, 28°51'S: 26°07'E, 1999, C. Haddad, abandoned Trinervitermes trinervoides mound ( NCA, 2006/1498) ; 1♂ same locality, 4 xi.2001, C. Haddad, under dung pad ( NCA, 2006/1479) . Gauteng: 1♀ Kloofendal Nat. Res., Roodepoort , 16.ii.1989, A. Leroy, under stone, exposed hillside ( NCA, 89/741) . Western Cape: 1♀ Anysberg Nat. Res., Vrede Cottages , 33°27.934'S: 20°35.218'E, 23.ix.2005, C. Haddad & R. Lyle, night collecting ( NCA, 2007/3936) .

Other material examined: LESOTHO: 2♀ 2♂ 4 juv. Mohale Dam, Island 1, 29°25.255'S: 28°05.985'E, 13 xii.2003, C. Haddad, among roots of fern ( NCA, 2006/1517) ; 1♂ Mohale Dam, Island 4, 29°25.349'S: 28°06.253'E, 15 xii.2003, C. Haddad, under rocks ( NCA, 2006/1516) ; 1♀ Mohale Dam, Island 5, 29°25.396'S: 28°05.903'E, 16.xii.2003, C. Haddad, under rocks ( NCA, 2006/1514) ; 1♂ near Ha Thlaku Village , 30°09.718'S: 28°14.175'E, 2122 m, 14 xi.2003, C. Haddad, under rocks, near stream ( NCA, 2006/1533) ; 1♀ Quthing, 17.iii.1949, Dr Brink, Dr Rudebeck, Swedish South Africa Expedition 1950–1951, Zoological Institute, University, Lund, rich meadows on horizontal layers of sandstone ( AMG) . NAMIBIA: 1♂ Vogelfederberg , 20.iv–18.v.1999, B. Wharton, pitfall trap ( CASC) . SOUTH AFRICA: Eastern Cape: 1♂ Alicedale, F. Cruden ( AMG) ; 1♂ Fort Brown , xii.1915, Walton ( AMG) ; 1♂ Grahamstown, 33 Oatlands road, 33°18'S: 26°32'E, 17.xii.1979, P.M.C. Croeser, in house ( NMSA) ; 1♀ 1♂ 5 imm. Jansenville district , “Klipfontein” farm, 32°54.492'S: 24°45.436'E, 29.ix–1 x.2008, R. Lyle, active searching ( NCA, 2008/2858) ; 1♂ 1♀ 1 juv. near Kirkwood, Dunbrody, 1902, J. O’Neil ( SAMC, 697) ; 1♂ Sundays River Valley , 23 xi.1999, H. Potgieter, citrus pitfall trap ( NCA, 2000/234). Free State : 1♂ 1 juv. Bloemfontein district , “Hopefield” farm, 28°54'S: 26°14'E, 15 xii.2001, C. Haddad, bluegum leaf debris ( NCA, 2006/1497) ; 1♀ Brandfort, Florisbad , 28°46'S: 26°05'E, 1250 m, 30.iii–26.iv.1988, L.N. Lotz, pres. traps ( NMBA, 3987) ; 1♀ same data ( NMBA, 8501) ; 1♀ Bloemfontein , 29°08'S: 26°10'E, 1440 m, 18.ii.1993, L.N. Lotz, in house ( NMBA, 5782) ; 1♀ Brandfort, Krugersdrift Dam , 28°42'S: 25°55'E, 1.i.1987, Museum staff, in canal ( NMBA, 9057) ; 1♀ Fauresmith, Boschrand 208, 29°56'S: 24°48'E, 22.iii.2005, L. Lotz, sweeping, beating ( NMBA, 10007) ; 1♀ Kimberley district, Benfontein Nat. Res. , 28°49.259'S: 24°50.155'E, 9.iii.2010, C. Haddad, base of grass tussocks ( NCA, 2010/295). Gauteng : 1♂ Witwatersrand, Marievale Bird Sanctuary , 26°20'S: 28°32'E, 8 xii.1990, V.D. & B. Roth ( CASC) . KwaZulu-Natal: 1♀ Pietermaritzburg, Scotsville , vii.1951, R.F. Lawrence, in dry leaves of garden ( NMSA, 5649). North West : 1♂ Potschefstroom district, Thabela Thabang Mountain Retreat, 26°51.828'S: 28°17.805'E, 29 x–5 xii.2009, R. Fourie & A. Grobler, pitfall traps, Vaal River bank ( NMSA, 22680). Northern Cape : 1♂ 8.9 mi W of Hanover, Eierfontein , i.1902, S.C. Cronwright-Schreiner ( SAMC, 10051) ; 1♂ same locality, xii.1901 – ii.1902, Schreiner ( SAMC, 11964) ; 1♀ Kathu District , “Sacha” farm, 27°42.500'S: 22°57.967'E, 24–27.ii.2003, C. Haddad, pitfall traps ( NCA, 2006/1500) ; 1♂ Lime Acres district , “Klien Papkuil” farm, 28°28.638'S: 23°43.461'E, 12–17.i.2008, R. Lyle, leaf litter ( NCA, 2008/2855) ; 3♀ same data ( NCA, 2008/2856) ; 1♀ same data ( NCA, 2008/2857) ; 3♂ Prieska District, Green Valley Nuts Estate , 22°56.683'S: 29°35.183'E, 23 xi–18 xii.2001, C. Haddad, leaf litter, Eucalyptus trees ( NCA, 2006/1502). Western Cape : 2♂ 1 juv. Buffels Bay, near Knysna , i.1910, W. Purcell ( SAMC, B2315 ) ; 3♂ Cape Town, dunes near Khayelitsha , 33°55'S: 18°25'E, 19.i.1989, R. Jocqué, fore dunes, sieved litter of shrub ( MRAC, 169681) ; 1♀ same data, 20.i.1989 ( MRAC, 169815) ; 1♀ Cape Peninsula, Muizenberg , 34°06'S: 18°27'E, 5–19.v.1991, R. Legg, dunes to the north ( MRAC, 173716) ; 1♀ same data, 18.vii–11.viii.1991 ( MRAC, 173801) ; 3♀ De Hoop Nat. Res., Potberg , 34°22.487'S: 20°31.980'E, 6.iv.2006, C. Haddad, leaf litter ( NCA, 2006/1511) ; 1♀ Kalk Bay Mountains , iii.1898, R.M. Lightfoot ( SAMC, 3136) ; 1♀ Kommetjie, 30 km S of Cape Town , 34°09'S: 22°10'E, 5.iv.2001, K. Muller, S. Prinsloo, D & S. Ubick, coastal strand, intertidal zone ( CASC) ; 1♀ Le Roux River , 10 km W Cango Caves, 33°30'S: 22°10'E, 4.ii.1991, V.D. & B. Roth ( CASC) ; 1♂ 3♀ 1 juv. Swartberg Nat. Res., Gamkaskloof , 15.ii.2001, Z. van der Walt, on soil ( NCA, 2002/201) ; 1♀ same locality, 14.iv.1995, M. de Jager, on soil, on slides ( NCA, 95/252) ; 1♂ Swartberg Nat. Res., Gamkaskloof, Die Hel , 33°21.0'S: 21°40.2'E, iii.2006, Z. van der Walt, collected by hand ( NCA, 2009/3678) .

Distribution: Found in Lesotho, Namibia and South Africa. In South Africa recorded predominantly in grassland, karoo and fynbos habitats ( Fig. 50 ).

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 43–49. Afroceto arca sp. n. female (43, 44) and male (45–49): (43) epigyne, ventral view; (44) vulva, dorsal view; (45) schematic representation of cusp arrangement on legs I and II; (46) left palp, ventral view; (47) left palp,retrolateral view;(48) variation of left palp,ventral view;(49) variation of left palp, retrolateral view. Scale bars (43, 44, 46–49) = 0.1 mm.

Fig. 50. The distribution of Afroceto arca sp. n. in southern Africa.