Trilacuna sinuosa, Tong, Yanfeng & Li, Shuqiang, 2013

Tong, Yanfeng & Li, Shuqiang, 2013, The first goblin spiders of the genus Trilacuna from Vietnam (Araneae, Oonopidae), Zootaxa 3709 (3), pp. 277-284 : 278-284

Trilacuna sinuosa sp. nov.

( Figs 4 E–H, 5)

Type material. 1 female holotype ( IZCAS Ar 19421), Tam Dao National Park, Vinh Phuc, Vietnam, leaf litter sieving in disturbed forest (21˚30.516′N, 105˚34.263′E, altitude ca. 509 meters), Pham Dinh-Sac, 17. V. 2007.

Etymology. The specific name is Latin, meaning “curving”, and refers to the strongly winding tube in the female epigastric region ( Fig. 4 F); adjective.

Diagnosis. The new species is similar to T. mahanadi Grismado & Piacentini , but can be distinguished by the numerous granulates on the sides of the carapace ( Figs 5 A–E), the longer postepigastric scutum ( Fig. 5 J), the strongly winding tube (swt) and straight, narrow sclerite (sns) in the female genital area ( Figs 4 E–H).

Description. Female. Completely chitinized. Body yellow-brown,chelicerae and sternum lighter, legs yellow. Habitus as in Figs 5 A, B. Body length 2.07; carapace 0.96 length, 0.75 width; abdomen 1.19 length, 0.71 width. Carapace broadly oval, slightly elevated, dorsal surface smooth, with three rows of short hairs between eyes and posterior border of elevation of carapace; sides with numerous granulates; lateral margin rebordered, with a row of short, finely hairs and small blunt denticles. Eyes six ( Figs 5 C–E), well developed, arranged in a compact group, about subequal, roundish; posterior row recurved from above, straight from front. Clypeus sinuous in frontal view, anterior lateral eyes separated from edge of carapace by about twice their diameter, with needle-like setae ( Fig. 5 E). Mouthparts: Chelicerae straight, proximal region with one hair with elevated hair base; labium rectangular, not fused to sternum, anterior margin deeply incised (ldi) ( Fig. 5 F); endites slender, distally not branched. Sternum ( Fig. 5 F) without radial furrows between coxae, surface finely reticulate; setae sparse, light, needle-like, evenly scattered. Abdomen: Ovoid, dorsal scutum not fused to epigastric scutum, postepigastric and epigastric scutum not fused, apodemes present, posterior spiracles connected by groove ( Figs 4 E, 5I); with two strongly sclerotized, recurved arches (sar) anterior to the posterior spiracles ( Fig. 4 E); booklung covers (boc) large, ovoid, surface smooth ( Figs 5 H, J). Leg spines: metatarsi I, II with 4 pairs of ventral spines each, tarsi I, II with 2 pairs of ventral spines each; legs III and IV without spines.

Female genitalia: Ventral view ( Figs 4 E, G): Uterus externus appearing as a procurved fold (pfo), ending in two dark brown knobs (dkn); anterior margin of postepigastic scutum (amp) recurved at middle; surface without external features except for a rugose surface around the epigastric furrow. Dorsal view ( Figs 4 F, H): with a strongly winding tube (swt) running posteriorly, then turning backwards, ending in a straight, narrow sclerite (sns); apodemes present (apo).

Male: Unknown.

Figures

FIGURE 5. Trilacuna sinuosa sp. nov., female. A, habitus, dorsal view; B, habitus, lateral view; C – F, prosoma, dorsal, lateral, frontal and ventral views; G, abdomen, anterior view; H, abdomen, lateral view; I, genital area, ventral view; J, abdomen, ventral view. Abbreviations: boc = booklung covers; ldi = labium deep incision. Scales: A, B, H, J, 0.4 mm; C – G, I, 0.2 mm.

FIGURE 4. A – D, Trilacuna hamata sp. nov., E – H, Trilacuna sinuosa s p. nov. A, C, E, G, female genital area, ventral view; B, D, F, H, female genital area, dorsal view. Abbreviations: amp = anterior margin of postepigastic scutum; apo = apodemes; dkn = dark brown knobs; fo = fold; pfo = procurved fold of uterus externus; rss = rectangular, sponge-like sclerite; sar = strongly sclerotized, recurved arches; sls = stick-like sclerite; sns = straight, narrow sclerite; swt = strongly winding tube. Scales: 0.2 mm.