Thysanina transversa, Lyle & Haddad, 2006

Lyle, Robin & Haddad, Charles R., 2006, A revision of the Afrotropical tracheline sac spider genus Thysanina Simon, 1910 (Araneae: Corinnidae), African Invertebrates 47, pp. 95-116 : 112-114

Thysanina transversa sp. n.

Figs 2–10 , 36–40

Etymology:This species name is Latin for ‘oblique’, and refers to the oblique alignment of the male embolus.

Diagnosis: This species is recognised by the oblique alignment of the male embolus and the semi-circular hoods covering the copulatory openings. A prominent retrolateral apophysis is found on the tibia, with two smaller apophyses. The patella has a subtriangular retrolateral apophysis.The epigyne has well sclerotised, curved copulatory openings that extend into the S-shaped spermathecae. For differences to T. similis , see description of the latter.

Description:

Female.

Measurements: CL 1.63–1.75, CW 1.23–1.6, AL 2.0–3.0, AW 1.23–2.9, TL 3.6–4.8, FL 0.75–1.0, SL 1.03–1.1, SW 0.85–0.9, AME–AME 0.08, AME–ALE 0.03, ALE– ALE 0.32, PME–PME 0.13, PME–PLE 0.10, PLE–PLE 0.58. Length of leg segments (sequence from femur to tarsus, and total): I 1.65+0.78+1.3+1.13+0.7=5.56; II 2.7+0.7+1.08+0.8+0.58=5.86; III 1.05+0.53+1.25+0.78+0.45=4.06; IV 1.88+0.5+ 0.55+1.38+0.55=4.86.

Carapace rising gradually to midpoint, declining sharply posterior to midpoint; surface smooth, short, fine setae scattered throughout ( Fig. 3 ); fovea short, indistinct, just posterior to midpoint; carapace bright orange to brown, border dark brown. Ocular region dark orange; all eyes surrounded by dark brown rings; AER procurved, lateral eyes larger than medians; clypeus height equal to 0.75 AME diameter at AME, 0.5 ALE diameter at ALE; AME separated by a distance equal to 0.75 their diameter, AME separated from ALE by distance equal to 0.25 AME diameter; PER slightly recurved, median eyes slightly larger than laterals; PME separated by distance slightly larger than their diameter, PME separated from PLE by distance equal to PLE diameter. Chelicerae dark orange to brown, slightly paler at fang base; promargin with three widely spaced teeth, distal tooth smallest, proximal tooth largest; retromargin with two closely placed teeth, subequal in size. Sternum pale orange to brown, darker around border; short, fine setae and long dark setae scattered throughout. Abdomen broader anteriorly, truncated posteriorly; dorsum pale yellow to white; chevron grey with prominent branches; no lateral line on dorsum; scattered long setae throughout. Legs I to IV uniform orange to brown; dense setae ventrally on metatarsi and tarsi; fine pale setae present on all segments; all four legs with scattered short, dark setae. Leg spination: femora: I pl 1 do 1, II pl 1 do 1, III do 1, IV do 1 rl 1; tibiae: IV vt 1; metatarsi: IV pl 1 rl 1; palpal spination: patellae pl 1; tibiae pl 2 do 2; tarsi pl 3 do 1 plv 1 rlv 1. Genital area strongly sclerotised, dark brown to orange in colour; copulatory openings situated in anterior half of epigyne, covered by semi-circular hoods; S-shaped spermathecae relatively small, with terminal receptaculae situated in posterior half of epigyne, not extending to epigastric fold ( Figs 36, 37 ).

Male.

Measurements: CL 1.23–1.98, CW 1.55–1.73, AL 1.8–2.35, AW 1.23–1.48, TL 3.55– 3.8, FL 0.08–0.13, SL 0.93–1.05, SW 0.93–1.0, AME–AME 0.11, AME–ALE 0.05, ALE–ALE 0.39, PME–PME 0.13, PME–PLE 0.15, PLE–PLE 0.67. Length of leg segments (sequence from femur to tarsus, and total): I 2.03+0.95+1.73+0.58+ 0.78=6.07; II 1.55+0.8+1.78+1.15+0.63=5.91; III 1.2+0.6+0.83+1.05+0.48=4.16; IV 1.75+0.73+1.55+1.78+0.5=6.31.

General appearance similar to female; male smaller with more compact abdomen than female; chevron darker with lateral line that ends at midpoint of abdomen. Eye region dark orange; all eyes surrounded by black rings; AER very slightly recurved, lateral eyes larger than medians; clypeus height 1.5 times AME diameter;AME separated by distance equal to their diameter, AME separated from ALE by distance equal to 0.75 AME diameter; PER recurved, eyes subequal in size; PME separated by distance equal to 1.75 their diameter, PME separated from PLE by distance equal to 1.5 times PME diameter. Chelicerae with scattered black setae on anterior surface; promargin with three teeth, distal tooth smallest, median and proximal teeth subequal in size; retromargin with two closely placed teeth, distal tooth slightly larger than proximal. Legs I to IV more robust and compact than those of female. Leg spination: femora: I pl 1 do 1,

II pl 1 do 1, III pl 1 do 1 rl 1–2, IV do 1 rl 2–4; tibiae: I plv 6 cusps, II plv 7 cusps, IV vt 1–2; metatarsi: I plv 5 cusps, II plv 7 cusps, III pl 1 plv 1, IV pl 1 rl 1; tarsi: I plv 2 cusps, II plv 1 cusps ( Figs 5–8 , 38 ); palpal spination: patellae do 2 rl 2 rlv 1, tibiae do 3 pl 1 rl 1, tarsi pl 2 rl 1. Palp orange throughout; prominent retrolateral tibial apophysis with two smaller median apophyses; triangular retrolateral patellar apophysis present; embolus twisted behind a sclerotised cover ( Figs 39, 40 ).

Holotype: ^‘ SOUTH AFRICA. / KWAZULU/NATAL. / Pongola Bush Reserve. / 27º19'S 30º29'E. / Paulpietersburg. / L Lotz. 3-XII-1994. // new nr. NMBA06737 // Corinnidae / Trachelinae / Thysanina transversa / HOLOTYPE //’ (NMBA # 6737).

Allotype: ơ ‘Lajuma / 23º02.255'S, 29º26.669'E / 25.xi.2004 / tree beating, Eugeria natalitia / M. Mafadza // Araneae / Corinnidae / Thysanina / transversa ơ / 2005/1894 det. C. Haddad//’ (NCA # 2005/1894).

Paratypes: 1ơ 1^‘1 Whitnall street, Grahamstown / 22.x.1978 / P. Croeser / in sac web on leaf in lemon / tree //’ ( NCA # 82 /376). 2ơ 1^‘Schagen / 15 km N.W / of Nelspruit / 19.viii.1997 / M. van den Berg / on macadamia tree //’ ( NCA # 98 /179). 4ơ 2^‘Schagen, 15km / N.W. of / Nelspruit / 7.x.1997 / M. van den Berg / on macadamia tree //’ ( NCA # 98 /178). 1ơ ‘ South Africa, KwaZulu-Natal / Greater St. Lucia Wetlands Park / False Bay Park / 14.X.2004, J. Esterhuizen / Tsetse fly traps //’ ( NCA # 2005 /184) .

Other material examined: SOUTH AFRICA: KwaZulu-Natal: 2ơ Ndumo Game Reserve, Pongola River floodplain, near pump, riverine forest, 26º54.323'S: 32º19.435'E, 27.vi.2006, beats, short shrubs, A. Honiball & E. Leuwin ( NCA 2006 /1229) . Limpopo: 1^Lajuma, 23º02.257'S: 29º26.661'E, 5.xi.2004, tree beating, Falcatus, M. Mafadza ( NCA 2005 /2032); 1ơ Sovenga Hill, near Polokwane , 23º53'S: 29º44'E, 15.xi.2004, short forest, tree beating, M.A. Modiba ( NCA 2005 /1865); 1ơ same data ( NCA 2005 /1866); 1ơ same data ( NCA 2005 /1867); 1ơ same data ( NCA 2005 /1868); 1ơ same locality, 2.xii.2004, short forest, tree beating, M.A. Modiba ( NCA 2005 /1876); 1ơ same locality, 4.xii.2004, short forest, tree beating, M.A. Modiba ( NCA 2005 /1877); 1ơ same data ( NCA 2005 /1878); 1^same locality, 27.xi.2004, short forest, active search, M.A. Modiba ( NCA 2005 /1874); 1ơ same data ( NCA 2005 /1875); 1ơ 1^same locality, 25.xi.2004, tall forest, tree beating, M.A. Modiba ( NCA 2005 /1869); 1ơ 1^same data ( NCA 2005 /1870); 1^same data ( NCA 2005 /1871); 1^same data ( NCA 2005 /1872); 1ơ 2 juv. same data ( NCA 2005 /1873) . Western Cape: 1^Diepwalle Forest Station , 22km NE Knysna, 33º57'S: 23º10'E, 10–13.i.1985, indigenous forest, C. Griswold & T. Meikle-Griswold ( NMSA) .

Distribution: Widely distributed in Western Cape, Eastern Cape, KwaZulu-Natal, Limpopo and Mpumalanga provinces of South Africa ( Fig. 41 ).

Natural history: This species was collected primarily from the foliage of shrubs and trees in a variety of woodland and forest habitats, at altitudes varying from 10 m a.s.l. (St Lucia) to 1700 m a.s.l. (Soutpansberg mountains).

Figures

Figs 2–10. Scanning electron micrographs of male Thysanina transversa sp. n.: (2) eye region; (3) fine setae on smooth carapace surface; (4) paired tarsal claws covered by dense claw tuft; (5) metatarsus I with ventral cusps; (6) tibia I with ventral cusps; (7) metatarsus II with larger ventral cusps; (8) tarsus II with ventral cusps, located between dense setae; (9) structure of peg-like cusps found on the anterior legs; (10) cusp socket in integument.

Figs 36–40. Thysanina transversa sp. n.: (36, 37) female: (36) epigyne, ventral view, (37) vulva, dorsal view; (38–40) male: (38) schematic representation of cusp arrangement on legs I and II, (39) left palp, ventral view, (40) left palp, retrolateral view. Scale bar (Figs 36, 37, 39, 40) = 0.1 mm.

Fig. 41. Distribution of Thysanina in the Afrotropical region.