Myrmarachne shelfordii Peckham & Peckham, 1907

Yamasaki, Takeshi & Ahmad, Abdul Hamid, 2013, Taxonomic study of the genus Myrmarachne of Borneo (Araneae: Salticidae), Zootaxa 3710 (6), pp. 501-556 : 549-551

Myrmarachne shelfordii Peckham & Peckham, 1907

( Figs 39 A–G, 40A–E)

Myrmarachne shelfordii Peckham & Peckham, 1907: 603 ; Yamasaki, 2010: 64, Figs 8–12 .

Type material examined. Lectotype male (MCZ; Catalog # 23056), Sarawak, BORNEO, G. W. Peckham & E. G. Peckham leg.

Non-type material examined. BORNEO: 2 males and 9 females, Poring Hot Spring, Kinabalu Park, Sabah, 13–14 XI 2010, T. Yamasaki leg.

Diagnosis. Hairy species; abdomen with posterior transverse broad black band. In males, retrolateral tibial apophysis of palp stout ( Figs 39 E–G). In females, copulatory atria round; spermathecae large, spherical; sclerotised copulatoryducts without twist ( Figs 40 D–E).

Measurements (male/female). Carapace length 2.20–(2.35)/2.35–2.50, width 1.60–1.68 (1.73)/1.54–1.68. Abdomen length 2.40–2.65 (2.70)/2.75–3.30. Chelicera length 2.15–2.75 (1.87). Sternum length 1.30–1.40 (1.33)/ 1.30–1.40. Width of eye row I 1.52–1.62/1.52–1.62; II 1.36–1.42 (1.50)/1.34–1.46; III 1.64–1.74/1.66–1.80. ALE– PLE 1.14–1.18 (1.15)/1.18–1.26; ALE–PME 0.58 (0.57)/0.58–0.62. Eye size: AME (0.49)–0.50/0.48–0.53, ALE 0.28–0.29 (0.25)/0.28–0.29, PME 0.08–(0.09)/0.08, PLE (0.29)–0.31/0.30–0.33.

Male ( Figs 39 A–G). Cephalic part almost flat dorsally, slightly higher than thoracic part. Dorsum of thoracic part weakly convex behind PLE, and abruptly sloping downward. Chelicera with one apical spur on its prolateral margin, and with five prolateral and nine to twelve retrolateral teeth; dorsal surface of chelicera wrinkled under microscopes. Fang almost straight except for curved tip, and without tooth-like apophysis. Sternum relatively broad; all coxae scarcely overlapped into sternum. Abdomen oval without constriction, with dorsal scutum; scutum oval without incisions on each lateral outline.

Palp ( Figs 39 E–G). Tegulum small and round with strongly curved seminal reservoir along prolateral and anterior margin of tegulum. Embolus forming two round coils; embolus coils occupying almost half of venter of cymbium. RTA stout and well-developed. Flange of RTA well-developed.

Leg spination. Femur I pd 1; patella I rv 1; tibia I pv 6, rv 5; metatarsus I pv 2, rv 2; femur II pd 0–1; tibia II pv 2–3, rv 3; metatarsus II pv 2, rv 2; femur III pd 1; femur IV pd 1.

Coloration and pilosity. Carapace brown to dark brown, entirely covered with white hairs; hairs on thoracic part more dense than that on cephalic part. Chelicera dark brown; in fresh specimens dorsal surface of chelicera with purple luster under microscopes. Maxilla, labium and sternum light brown. Coxae I and II cream; coxae III and IV cream, slightly tinged with pale orange. Abdomen cream in anterior part and posterior tip, and with transverse broad black band in posterior part; dorsal scutum transparent dark brown. White hairs roughly forming transverse band in anterior part.

Female ( Figs 40 A–E). Carapace almost same as in males. Chelicera with six prolateral and nine or ten retrolateral teeth. Sternum similar to that of males. Abdomen oval with indistinct dorsal scutum; scutum without incision.

Epigyne ( Figs 40 D–E). Copulatory atria containing openings round. Spermathecae large, spherical; sclerotised copulatory ducts strongly curved along inner margins of copulatory atria, and proximally weakly swollen, without twist.

Leg spination. Patella I rv 1; tibia I pv 6–7, rv 5–6; metatarsus I pv 2, rv 2; tibia II pv 3, rv 3; metatarsus II pv 2, rv 2.

Coloration and pilosity. Carapace light brown, covered with white hairs. Chelicera dark brown. Maxilla and labium light brown to brown. Sternum pale brown. Coxae brownish cream. Abdomen similar to that of males.

Distribution. Borneo (Peckham & Peckham 1907).

Remarks. The females of Myrmarachne shelfordii are here recorded for the first time. M. shelfordii is similar to M. exasperans (Peckham & Peckham 1892) , but they are distinguished by markings on the abdomen. These species are very similar in the structures of the male palp and the female epigyne.

Biology. Myrmarachne shelfordii makes retreats mixed with dead plant fragments on the underside of leaves. The present material was collected from leaves of large ginger plants along a trail in a rainforest.

Figures

FIGURE 39. M. shelfordii, male. A, body, dorsal view; B, chelicera and carapace, lateral view; C, maxillae, labium, sternum and coxae; D, chelicera and fang, ventral view; E, palp, ventral view; F, palp, lateral view; G, palp, dorsal view. (Scales. A – D: 1 mm; E – G: 0.25 mm)

FIGURE 8. M. biseratensis, male. A, body, dorsal view; B, chelicera and carapace, lateral view; C, chelicera and fang, ventral view; D, maxillae, labium, sternum and coxae; E, palp, ventral view; F, palp, lateral view; G, palpal tibia, dorsal view. (Scales. A – D: 1 mm; E – F: 0. 25 mm)

FIGURE 9. M. biseratensis, female. A, body, dorsal view; B, body, lateral view; C, maxillae, labium, sternum and coxae; D and F, internal structure of epigyne, ventral view; E, internal structure of epigyne, dorsal view. (Scales. A – C: 1 mm; D – E: 0.25 mm; F: 0.10 mm)

FIGURE 10. M. borneensis, male. A, chelicera and carapace, dorsal view; B, abdomen, dorsal view; C, chelicera and carapace, lateral view; D, maxillae, labium, sternum and coxae; E, chelicera and fang, ventral view; F, cymbium, embolus and tegulum; G, palpal tibia, ventral view. (Scales. A – E: 1 mm; F – G: 0.25 mm)

FIGURE 11. M. brevichelicera sp. nov., male. A, body, dorsal view; B, chelicera and carapace, lateral view; C, chelicera and fang, ventral view; D, maxillae, labium, sternum and coxae; E, palp, ventral view; F, palp, lateral view; G, palp, dorsal view. (Scales. A – D: 1 mm; E – G: 0. 25 mm)

FIGURE 12. M. brevichelicera sp. nov., female. A, body, dorsal view; B, chelicera and carapace, lateral view; C, maxillae, labium, sternum and coxae; D and F, internal structure of epigyne, ventral view; E, internal structure of epigyne, dorsal view. (Scales. A – C: 1 mm; D – E: 0.25 mm; F: 0.10 mm)

FIGURE 40. M. shelfordii, female. A, body, dorsal view; B, chelicera and carapace, lateral view; C, maxillae, labium, sternum and coxae; D, E, internal structure of epigyne, ventral view. (Scales. A – C: 1 mm; D: 0.25 mm; E: 0.10 mm)