Nesiergus gardineri ( Hirst 1911 ) Hirst, 1911

Guadanucci, José Paulo L. & Gallon, Richard C., 2008, A revision of the spider genera Chaetopelma Ausserer 1871 and Nesiergus Simon 1903 (Araneae, Theraphosidae, Ischnocolinae), Zootaxa 1753, pp. 34-48 : 46-47

Nesiergus gardineri ( Hirst 1911) n. comb.

Figures 35–40

Chaetopelma gardineri Hirst 1911: 383 , fig. 1 (D♂Ψ); Benoit 1978: 417, figs. 5a–f (♂Ψ). Chaetopelma gardinieri (lapsus): Smith 1990: 112, figs. 632–651 (♂Ψ).

Material examined. Type material: Holotype ɗ ( BMNH 10.5.1.5–6); Paratype 6Ψ ( BMNH 10.5.1.5–6) from Silhouette, 1905; Paratype 1Ψ ( BMNH 10.5.1.5–6) from Cascade; Paratype 1Ψ ( BMNH 10.5.1.5–6) from Félicité; Paratype 1Ψ ( BMNH 10.5.1.5–9) from Mahé; Paratypes 2Ψ 2 imms. ( BMNH 10.5.7–9) from Praslin. All from the Seychelles islands, collected by the Percy Sladen Expedition. All examined.

Additional material examined: SEYCHELLES: 1Ψ ( BMNH 10.5.1.5–6) Percy Sladen Expedition leg.; Big Sister: 1ɗ ( MRAC 177120) Mühlenberg leg., 17.IX.1975; 1ɗ ( MRAC 177140) Mühlenberg leg., 17.IX.1975; 2Ψ ( MRAC 177118) Mühlenberg leg., 17.IX.1975; Silhouette 1Ψ ( ZMB 32337); Mahé: 1Ψ ( MRAC 145699), Benoit leg., 16.VIII.1972.

Diagnosis: Males are distinguished from those of N. halophilus by the absence of a keel on the palpal bulb embolus ( Figs. 38–39 ), by the tibial apophysis ( Fig. 37 ) not being as wide and developed as in N. halophilus , and by metatarsus IV not being curved laterally. Females differ from those of N. halophilus by their spermathecal receptacula being even in width throughout their length ( Fig. 40 ).

Description: Male (holotype). Total length 15.7 (note: only chelicera and carapace – abdomen missing). Carapace: length 11.3, width 8.6. Eye tubercle: length 1.2, width 1.6; anterior row procurved, posterior row slightly recurved, clypeus very narrow, nearly absent. Chelicerae with 14 teeth of similar size on promargin. Labium as long as wide with ca.30 cuspules ( Smith 1990 – specimen now with labium and part of sternum damaged). Maxillae with ca.100 cuspules. Sternum oval. Fovea transverse. Palp: femur 5.3/ patella 3.5/ tibia 4.4/ cymbium 1.9/ total 15.1. Legs I: femur 8.5/ patella 5.5/ tibia 7.2/ metatarsus 5.9/ tarsus 3.6/ total 30.7. II: 7.6/ 4.7/ 5.8/ 5.7/ 3.3/ 27.1. III: 7.3/ 3.9/ 5.2/ 7.1/ 3.5/ 27.0. IV: 9.8/ 4.5/ 8.1/ 11.0/ 4.3/ 37.7. Spines. Palp: tibia (v) 0–0–1, (p) 0–1–0. Legs: I: femur (d) 0–0–p1, metatarsus (v) 0–0–ap 1. II: femur (d) 0–0–p1, tibia (v) 2–0– ap3, (p) 0–0–1, metatarsus (v) ap 1. III: femur (d) 0–r1–4, patella (p) 1, tibia (v) 1–2–ap3, (p) 1–1–1, (r) 1–0– 1, metatarsus (v) 2–3–ap3, (p) 0–1–1, (r) 0–1– 1. IV: femur (d) 0–0–r2, patella (p) 1, tibia (v) 2–2–ap4, (p) 0– 0–1, (r) 1–1–1, metatarsus (v) 2–1–2+ap3, (p)1–1–1, (r) 1–0–1. Palpal bulb with long thin embolus, slightly helicoid ( Figs. 38–39 ). Tibial apophysis comprising two branches, strongly fused basally ( Fig. 37 ). Prolateral branch short, wide with adjacent spine. Retrolateral branch slightly longer than prolateral, bearing apical row of short spines. Metatarsus I straight, bends externally to apophysis. Metatarsal scopulae extent (ventral surfaces only): I along entire length; II on distal three-quarters; III on slightly more than distal half; IV on slightly less than distal half. Tarsal scopulae (ventral surfaces only): I–II undivided; III–IV divided by longitudinal band of thick setae.

Female (paratype BMNH 10.5.1.5–6). Total length 23.0. Carapace length 8.2, width 6.6. Eye tubercle length 1.1, width 1.3; anterior row strongly procurved, posterior row recurved, clypeus very narrow. Labium: length 0.9, width 1.4. Sternum: length 3.3, width 3.2. Chelicerae with 14 teeth of similar size on promargin. Labium as long as wide with 31 cuspules. Maxillae with ca.100 cuspules. Sternum rounded. Fovea transverse. Palp: femur 3.8/ patella 2.5/ tibia 3.2/ tarsus 2.2/ total 11.7. Legs I: femur 5.9/ patella 3.9/ tibia 4.5/ metatarsus 3.6/ tarsus 2.3/ total 20.2. II: 5.0/ 3.4/ 3.7/ 3.3/ 2.1/ 17.5. III: 4.8/ 2.8/ 3.2/ 4.3/ 2.3/ 17.4. IV: 6.8/ 3.4/ 5.7/ 7.1/ 3.0/ 26.0. Spines. Palp: tibia (v) 0–0–ap1. Legs: I: metatarsus 0–0–ap 1. II: metatarsus (v) 0–0–ap 1. III: femur (d) 0–0–r1, patella (p) 1, tibia (v) 0–1–ap2, (p) 1–2–ap1, (r) 1–1–0, metatarsus (v) 2–2–ap3, (p) 0–1–1, (r) 0– 1– 1. IV: femur (d) 0–0–r1, tibia (v) 1–1–ap3, (p) 1–1–0, (r) 1–0–1, metatarsus (v) 3–2–ap3, (p) 1–1–1, (r) 0– 1–1. Spermathecae comprising two receptacula, each slightly longer than wide, distal portion swollen and more sclerotised ( Fig. 40 ). Metatarsal scopulae extent (ventral surfaces only): I–II along entire length; III on slightly more than distal half; IV on slightly less than distal half. Tarsal scopulae (ventral surfaces only): I undivided; II–IV divided by longitudinal band of thick setae.

Distribution: Known from the islands of Silhouette, Mahé, Félicité, Praslin and The Sisters, Seychelles.

Ecology: Spiders inhabit endemic forests, presumably fossorial. Males are mature in September.

Remarks: Males of N. gardineri have the branches of their tibial apophysis strongly fused basally and the prolateral branch is as long as wide. For these reasons Chaetopelma gardineri is transferred to Nesiergus .

Figures

FIGURES 35 – 40. Nesiergus gardineri (Hirst 1911) (holotype male, paratype female BMNH 10.5.1.5 – 6). 35. Habitus, dorsal view, male. 36. Prosoma, ventral view, male. 37. Male tibial apophysis, ventral-prolateral view. 38, 39. Palpal bulb, prolateral view (38), retrolateral view (39). 40. Spermathecae, dorsal view. Scale = 1 mm.