Thysanina absolvo, 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 : 102-105

Thysanina absolvo sp. n.

Figs 16–20

Etymology: This species name is Latin for ‘free’, taken from the terra typica, Free State Province in South Africa, where the entire type series was collected.

Diagnosis: This species can be recognised from others by the retrolateral hair tuft and the uniquely curved embolus of the male palp. The female can be recognised by the very large bean-shaped spermathecae and looped entrance ducts.

Description:

Female.

Measurements: CL 1.23–1.53, CW 1.15–1.48, AL 1.95–1.48, AW 1.45–1.8, TL 3.3–3.8, FL 0.11–0.12, SL 0.78–0.88, SW 0.73–0.83, AME–AME 0.08, AME–ALE 0.05, ALE– ALE 0.32, PME–PME 0.12, PME–PLE 0.09, PLE–PLE 0.45. Length of leg segments

* The female syntype was examined by Dr Martin Ramírez (Museo Argentino de Ciencias Naturales, Buenos

Aires, Argentina) during 2001, and his sketches of the female epigyne correspond adequately with those provided for this species here.

(sequence from femur to tarsus, and total): I 1.4+0.7+1.25+0.9+0.53=4.78; II 1.2+0.63+ 0.9+0.78+0.3=3.81; III0.9+0.45+0.58+0.78+0.23=2.94; IV1.45+0.63+1.2+1.23+0.3=4.81.

First three quarters of carapace evenly high, with relatively steep decline in last quarter; surface smooth, covered in short setae; fovea small, distinct, at two-thirds carapace length; carapace orange to brown in colour. Ocular region dark orange to brown with dark brown to black rings around eyes; AER slightly procurved, lateral eyes very slightly larger than medians; clypeus height equal to AME diameter;AME separated by distance equal to their diameter;AME separated from ALE by 0.25 AME diameter; PER slightly recurved, median eyes larger than laterals; PME separated by distance equal to their diameter, PME separated from PLE by slightly less than PLE diameter. Chelicerae dark orange to brown, slightly paler near fang base; scattered black setae on anterior surface; longer setae towards fang base; three promarginal teeth, two large, subequal in size, near fang base; third tooth small, far from fang base on promargin; three retromarginal teeth, equal in size, on single base. Sternum orange, brown towards border; long brown setae scattered on sternum. Abdomen broader anteriorly, truncated posteriorly; dorsum creamy white; grey chevron with darkened median line, light grey transverse branches dorsally, dark grey lines laterally; surface smooth with short fine setae throughout. Legs I to IV yellow to orange; tibiae, metatarsi and tarsi with dense long, dark setae ventrally; remaining leg segments covered in fine, less dense setae. Regular leg spines, cusps absent; palpal spination: patellae pl 2, tibiae pl 1. Genital area sclerotised, dark brown; copulatory openings in curved depression, situated anteromedially in epigyne near looped entrance ducts; spermathecae very large, bean-shaped, with darkened terminal receptacles situated anteriorly ( Figs 16, 17 ).

Male.

Measurements: CL 1.7–1.73, CW 1.5–1.55, AL 1.9–2.2, AW 1.3–1.55, TL 3.63–3.9, FL 0.1–0.11, SL 0.98–1.05, SW 0.8–0.9, AME–AME 0.01, AME–ALE 0.03, ALE– ALE 0.3, PME–PME 0.1, PME–PLE 0.05, PLE–PLE 0.4. Length of leg segments (sequence from femur to tarsus, and total): I 1.75+0.8+1.5+1.15+0.55=5.75; II 1.4+0.7+1.23+0.88+0.47=4.68; III 0.98+0.53+0.69+0.9+0.36=3.46; IV 1.45+0.65+ 1.23+1.38+0.42=5.13.

General appearance similar to female; male smaller and colouration darker; abdomen creamy white; dark grey chevron with more prominent transverse branches than female. AER slightly procurved, eyes subequal in size; clypeus height equal to AME diameter; medians separated by their diameter; AME separated from ALE by slightly less than 0.5 AME diameter; PER recurved, median eyes larger than laterals; PME separated by 1.5 times their diameter; PME separated from PLE by distance equal to PME diameter. Chelicerae granular with a few scattered long, dark setae over surface; three well separated promarginal teeth, distal tooth smallest, far from fang base on promargin; three retromarginal teeth, close together, not on single base, proximal tooth smallest, median largest. Legs I to IV similar in colouration to females, more compact and stout. Leg spination: tibiae: I plv 8 cusps; metatarsi: I plv 8, rlv 1 cusps, II plv 8 cusps; tarsi: I plv 8 cusps, II plv 5 cusps ( Fig. 18 ); regular leg spines, palpal spines absent. Palp orange brown throughout; small median ventral tibial apophysis; embolus beginning medially in cymbium, curving prolaterally then retrolaterally, with distal terminal, tear-shaped embolus tip; retrolateral hair tuft ventrally on cymbium ( Figs 19, 20 ).

Holotype: ^‘NMBA 9087 / S. Africa F.S. Brandfort Florisbad 1250m / 2846S/2605E 20-4 7-8 1988 / L.N. Lotz Pres. traps (9A) // new nr. NMBA08727 // Corinnidae / Trachelinae / Thysanina absolvo / HOLOTYPE //’ (NMBA # 8727).

Allotype: ơ ‘Ficksburg / 7.iii.1989 / M. Filmer / Bush beating / rocky mountainside // Araneae / Corinnidae / Trachelinae / Thysanina / absolvo ALLOTYPE ơ / 89/865 det. R. Lyle //’ (NCA # 89/865).

Paratypes: 1^‘NMBA 6564 / — 7 1990 L.N. Lotz / S. Africa O.F.S. Bloemfontein / Bloemfontein, Grant’s Hill / 1490m 2906S/2613E / Pres. traps // new nr. NMBA06227 //’ ( NMBA # 6227 ) . 1 ^‘NMBA 6564 / — 8 1990 L.N. Lotz / S. Africa O.F.S. Bloemfontein / Bloemfontein, Grant’s Hill / 1490m 2906S/2613E / Pres. traps // new nr. NMBA06229 //’ ( NMBA # 6229 ) . 1^‘R. S.A., Free State / Deelhoek farm / Bloemfontein district / 28º54'S, 26º07'E / 19.I.2001 / (under rocks in grassland) //’ ( NCA # 2005 /989) . 1^‘ S. Africa; O.F.S.; Florisbad / SE 2826Cc; Mus. Staff / June ’85; Pres. traps // new nr. NMBA00739 //’ ( NMBA # 739 ) . 1ơ ‘R. S.A., Free State Province / Erfenis Dam Nature Reserve / 28º30.431'S, 26º48.457'E / 24.II.2006, C. Haddad / At base of Themeda grass //’ ( NCA # 2006 /460) . 1ơ ‘R. S.A., Free State Province / Erfenis Dam Nature Reserve / 28º30.431'S, 26º48.457'E /, 24.II.2006, R. Lyle / Beats, short shrubs //’ ( NCA # 2006 /461) . 1ơ ‘R. S.A., Free State Province / Erfenis Dam Nature Reserve / 28º30.431'S, 26º48.457'E / 28.II.2006, R. Lyle / Beats, short shrubs //’ ( NCA # 2006 /462) . 2ơ 1^‘NMBA 10004 / South Africa, FS / Fauresmith, Boschrand 208 / 2956S/2448E, / L Lotz , 21 Mar 2005 / sweeping, beating //’ ( NMBA # 10004 ) .

Distribution: Distributed in the eastern and central parts of Free State Province, South Africa ( Fig. 41 ).

Natural history: This species appears to be associated primarily with the lower strata of grassland ecosystems, and was collected from the ground surface, grass and short shrubs.

Figures

Figs 16–20. Thysanina absolvo sp. n.: (16, 17) female: (16) epigyne, ventral view, (17) vulva, dorsal view; (18–20) male: (18) schematic representation of cusp arrangement on legs I and II, (19) left palp, ventral view, (20) left palp, retrolateral view. Scale bar (Figs 16, 17, 19, 20) = 0.1 mm.

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