Xenonemesia otti, Indicatti, Rafael Prezzi, Lucas, Sylvia Marlene & Brescovit, Antonio Domingos, 2007

Indicatti, Rafael Prezzi, Lucas, Sylvia Marlene & Brescovit, Antonio Domingos, 2007, A new species of the spider genus Xenonemesia Goloboff and first record of X. platensis Goloboff from Brazil (Araneae, Mygalomorphae, Microstigmatidae), Zootaxa 1485, pp. 43-49 : 44-49

Xenonemesia otti n. sp.

( Figs. 5–8 , 18–28 )

Types. Male holotype from riverheads of the Arroio Itapuã, Viamão, Rio Grande do Sul, Brazil, Sept. 11, 2001, L. E. C. Schmidt & R. Ott leg., deposited in MCN 34287. Paratypes with the same data as holotype, two males (MCN 42582; IBSP 12782) and one female (MCN 42581).

Additional material examined. One male with same data as holotype, (MCN 42583).

Etymology. The specific name is in honour of Ricardo Ott, Brazilian arachnologist from the Museu de Ciências Naturais of the Fundação Zoobotânica do Rio Grande do Sul.

Diagnosis. X. otti n. sp. differs from X. platensis by males having a longer and sinuous apical region of the embolus ( Figs. 5–7 ) and in females, by the twisted duct with a long apical area in the spermathecae ( Fig. 8 ).

Description. Male (holotype). Coloration pattern: carapace brown–orange brownish orange and legs brown with light–brown markings ( Figs. 18–19 ). Abdomen dorsally and ventrally dark yellow with random symmetric black markings ( Figs. 18, 20 ). Total length, excluding chelicerae, 7.20. Carapace 3.70 long, 2.92 wide, fovea short, procurved ( Fig. 19 ); clypeus narrow, 0.12. Anterior eye row procurved, posterior slightly recurved. Eye sizes: AME 0.18, ALE 0.24, PME and PLE 0.16. Overall shape of eye group trapezoidal, ratio wider than long. Basal segment of chelicerae with 7–8 teeth in row and rastellum with very strong setae. Intercheliceral tumescence small, pale yellow covered by few hairs. Labium 0.25 long, 0.62 wide, without cuspules ( Fig. 22 ). Each endite with 10–11 cuspules. Serrula absent. Sternum circular 1.60 long, 1.56 wide. Six sternal sigilla: posterior submarginal, 1/4 larger than the anterior. Palp: measurements, femur 1.50, patella 0.80, tibia 1.20, cymbium 0.50, total 4.00; spination, femur d1-1-1, tibia p0-0-1, r0-0-1. Leg measurements. I: femur 2.50, patella 1.65, tibia 1.82, metatarsus 1.51, tarsus 1.00, total 8.48. II: 2.20, 1.45, 1.40, 1.50, 1.08, 7.63. III: 2.08, 1.30, 1.52, 2.00, 1.10, 8.00. IV: 2.85, 1.50, 2.10, 2.95, 1.30, 10.70. Spination. I: femur d1-1-1- 1-1p, patella d0-0-1p, tibia v1-3 -0-3-2ap, p1-0-1, megaspine absent, metatarsus v1 r-0- 2. II: femur d1-1-0-1ap, patella d0-0-1p, tibia v1 r-1r-0-3ap, p0-1-1 metatarsus d0-1p-1p, v1 r-1r-0-3ap, tarsus 0. III: femur d1-2-1r-1r, patella d2-2-1p-0, tibia d1r-0-2, v2-1 p-3ap, p1-1-0, metatarsus d1-2-1p-3, v1-1 p-3ap, p1-0- 1. IV: femur d1-1- 2-1r-1r, patella r1r-1r-0, tibia d1-2-0-0, v2-2 -0-3ap, p0-1-0, r0-1-0, metatarsus d1-1r-1p-2-2, v2-2 -3ap, p1-1- 1. Tarsi I–IV entire. Scopulae on tarsi I, II entire. Superior tarsal claws large with two rows of 3–4 teeth on I; 5–6 on II, 5–7 on III and 6–8 on IV. Four spinnerets: PLS three-segmented, basal 0.29, median 0.19, apical segment 0.08 long, domed.

Female. (paratype). Coloration pattern as in male ( Figs. 23, 25, 26 ), except leg markings much darker. Total length, excluding chelicerae, 8.80. Carapace 3.90 long, 3.00 wide, fovea short, procurved ( Fig. 23 ). Clypeus narrow, 0.11. Anterior eye row procurved, posterior slightly recurved. AME 0.18, ALE 0.22, PME 0.17, PLE 0.22. Overall shape of eye group trapezoidal, wider than long. Basal segment of chelicerae with eight teeth in each row and rastellum with very strong setae. Labium 0.29 long, 0.70 wide, without cuspules ( Fig. 24 ). Endites with 8–9 cuspules. Sternum circular 1.56 long, 1.61 wide. Six sternal sigilla: posterior and middle submarginal; posterior 1/3 larger than anterior. Palp measurements: femur 1.30/ patella 0.90/ tibia 0.78/ cymbium 0.80/ total 3.78; spination: tibia v0-0-2ap. Leg measurements: I: femur 2.05/ patella 1.55/ tibia 1.40/ metatarsus 0.95/ tarsus 0.70/ total 6.65; II: 1.65/ 1.25/ 0.90/ 0.90/ 0.80/ 5.50; III: 1.70/ 1.05/ 0.80/ 1.25/ 0.95/ 5.75; IV: 2.00/ 1.15/ 1.30/ 1.65/ 1.10/ 7.20; spination: I: none II: metatarsus v0-1r-2ap; III: patella d1p- 1p-1p, tibia d0-1-0, v0-0-2ap, p0-1-0, metatarsus d1r-1p-0-2ap, v1 p-0-3ap, p0-1-1-0, tarsus 0; IV: tibia v0-0- 2ap, p0-1-0, r0-1-1-0, metatarsus d1r1r-1r-1p-2ap, v0-0-1p-3ap, p1-1-0. Palp with prolateral row of two teeth. Tarsi I–IV entire. Scopulae entire on tarsi I. Superior tarsal claws large with two rows of 1–2 teeth on tarsi I, 2–3 on tarsi II, 2–4 on tarsi III and 1–3 on tarsi IV. Four spinnerets, PLS three segmented, basal segment 0.50, median segment 0.22, apical segment domed 0.10 long.

Variation. Four males: total length 6.80–7.20; carapace 3.40–3.70; femur I 2.40–2.50; endites with 7–9 cuspules.

Remarks. Consistent with the generic diagnosis, the third claw is entirely absent.

Distribution. Southern Brazil: Rio Grande do Sul.

Figures

FIGURES 1 – 8. 1 – 4. Xenonemesia platensis. 1 – 3. Left palpal bulb. 1. Prolateral view; 2. Ventral view; 3. Retrolateral view; 4. Female spermathecae, dorsal view (female from Parque Nacional El Palmar, Entre Ríos, Argentina); 5 – 8. X. otti n. sp. 5 – 7. Left palpal bulb. 5. Prolateral view; 6. Ventral view; 7. Retrolateral view; 8. Female spermathecae, dorsal view. Scale bars = 0.5 mm.

FIGURES 18 – 26. Xenonemesia otti n. sp. 18 – 22. Male. 18. Body, dorsal view; 19. Carapace, dorsal view; 20 – 21. Abdomen. 20. Dorsal view; 21. Ventral view; 22. Sternum, ventral view. 23 – 26. Female. 23. Body, dorsal view; 24. Sternum, ventral view; 25 – 26. Abdomen. 25. Ventral view; 26. Lateral view. Scale bars = 1 mm.

FIGURES 27 – 28. Xenonemesia otti n. sp., male 27. Male, book-lung opening, ventral view; 28. Female, posterior lateral spinneret, apical area.