Birabenella chincha, Piacentini & Grismado & Ramírez, 2017

Piacentini, Luis N., Grismado, Cristian J. & Ramírez, Martín J., 2017, An Update of the Goblin Spider Genus Birabenella Grismado, 2010 (Araneae: Oonopidae), with the Description of Three New Species, American Museum Novitates 2017 (3883), pp. 1-20 : 14-17

Birabenella chincha , new species

Figures 1D, G ; 3 ; 8 ; 9 ; 10E, F ; 11

TYPE MATERIAL: Male holotype, two males and three female paratypes from Peru: Ica: Pisco , -13.70000°, -76.18333°, Sept. 01, 2011, Giraldo A . ( MEKRB, PBI _OON 49999) .

ETYMOLOGY: The specific epithet refers to Chincha people, whose ancient pre-Inca civilization flurished in the region of Peru where the holotype was found .

DIAGNOSIS: Both sexes are recognized by the conspicuous sternal furrows between coxae (figs. 8E, 9F), and by the nearly straight posterior eye row from above (fig. 9D); males are similar to B. kamanchaca by the relatively simple (only two) flattened terminal projections of bulb, but differ in their shape and orientation (figs. 3A–E, 10E); females are similar to those of B. pizarroi by the nearly oval anterior sclerite and straight copulatory duct, but differ by having a strongly recurved sclerotized bar, that appears as two curved, scimitar-shaped branches, and by the different path of the internal tube of the posterior receptacle (fig. 10F).

DESCRIPTION. MALE (PBI_OON 49999). CEPHALOTHORAX: Prosomal setae light. Eyes: ALE largest; posterior eye row straight from above, procurved from front; PLE-PME separated by less than PME radius. Sternum as long as wide, with radial furrows between coxae I–II, II–III, III–IV, surface smooth; setae light, evenly scattered. Mouthparts: labium subpentagonal; with 1 or 2 setae on anterior margin. Endites with lateral furrow that bisects them in two parts, dorsal and ventral; with two darkened, curved setae on tip, the larger one with twisted apex (fig. 10E). ABDOMEN: Dorsum and ventral setae light. LEGS: spines absent. GENITALIA: Tarsal organ of cymbium with proximal ridge and two receptors (apparently fused at their bases) one larger and other smaller (fig. 1G); femur one to two times as long as trochanter; membranous fundus oval, in center of the spherical base of bulb, from where arises weakly sclerotized seminal duct; gently curved along almost all its length, distal part with two flattened, compressed, distal projections of bulb that arise from an alveolus: one on prolateral side, bent to ventral, and another widened, ventrally directed, less sclerotized. Digitiform projection on ventral part of the bulb, near distal part, curved to retrolateral side (figs. 3A–E, 10E).

FEMALE (PBI_OON 49999). As in male except as noted. Palp spines absent. LEGS: Tarsi I superior claws examined by SEM, with six teeth each (fig. 3F). Tarsal organ of leg I with inconspicuous proximal ridge, apparently with only one receptor (fig. 1D). GENITALIA (fig. 10F): Dorsal view: anterior sclerite large, nearly spherical, apparently with lumen; two thin consecutive transverse sclerotized bars separate it from the posterior part of genitalia, that has strongly recurved sclerotized bar as two curved, scimitar-shaped branches (with muscle insertions on middle of each branch); copulatory opening led apparently to thick-walled, sinuous copulatory duct. Posterior receptacle with anterodorsal thick wall, with reticulated surface and irregular shape, internal tube describing two loops and converging on anteromedian part.

OTHER MATERIAL EXAMINED: Same locality as the types, Apr. 01, 2011, Giraldo A., 1♀ ( MEKRB PBI _OON 49998) .

Figures

FIG. 1. Birabenella spp., morphology of tarsal organs. A–D, leg I, E, leg II, F, leg III, G, cymbium. A, B. homonota Grismado (female PBI_OON 14990), B, B. pizarroi Grismado (female holotype PBI_OON 14992), C, E, F, B. kamanchaca, n. sp. (female PBI_OON 42434), D, B. chincha n. sp. (female paratype PBI_OON 49999), G, B. chincha n. sp. (male paratype PBI_OON 49999). Arrows = receptors,? = probable receptors. Scale bars: A, 0.5 mm; B, 0. 2 mm; C–E, G, 5 mm; F, 2 mm.

FIG. 3. Birabenella chincha, n. sp. A–E, male paratype, F–G, female paratype (both specimens PBI_OON 49999). A–E, left palp, copulatory bulb, A, prolateral view, B, same, detail of the distal part, C, dorsal prolateral, D, apical, E, apical ventral. F, leg I tarsal claws; G, trichobothrium socket of metatarsus I. Scale bars: A, F, 50 mm; B–E, 20 mm; G, 10 mm.

FIG. 8. Birabenella chincha, n. sp., female paratype (PBI_OON 49999). A–C, habitus (A, dorsal; B, lateral; C, ventral); D, E, cephalothorax (D, dorsal; E, ventral); F, epigastric area, ventral. Scale bars: A–C, 500 mm; D–F, 200 mm.

FIG. 9. Birabenella chincha, n. sp., male holotype. A–C, habitus (A, dorsal; B, lateral; C, ventral); D–F, cephalothorax (D, dorsal; E, lateral; F, ventral); G, carapace, anterior view. Scale bars: A–C, 500 mm; D–G, 200 mm.

FIG. 10. Birabenella spp., genitalia. A–B, B. kamanchaca, n. sp. (male holotype and female paratype (PBI_OON 42429); C–D, B. portai, n. sp. (male holotype and female paratype); E–F, B. chincha, n. sp. (male holotype and female paratype PBI_OON 49999). A, C, E, left palp, prolateral view); B, D, F, female vulva, cleared, dorsal view. Arrows = ventral tegular digitiform process. Abbreviations: as = anterior sclerite, cd = copulatory duct, pr = posterior receptacle. Scale bars: 100 mm.

FIG. 11. Distribution of the species of Birabenella: black triangles indicate new species described in this paper; black circles indicate those previously described.