Trilacuna mahanadi Grismado and Piacentini, 2014

Grismado, Cristian J., Deeleman, Christa, Piacentini, Luis N., Izquierdo, Matías A. & Ramírez, Martín J., 2014, Taxonomic Review Of The Goblin Spiders Of The Genus Dysderoides Fage And Their Himalayan Relatives Of The Genera Trilacuna Tong And Li And Himalayana, New Genus (Araneae: Oonopidae), Bulletin of the American Museum of Natural History 2014 (387), pp. 1-108 : 49-54

Trilacuna mahanadi Grismado and Piacentini , new species

Figures 36– 38 , 39E–F

TYPES: Male holotype and two female paratypes from India: West Bengal: Darjeeling: Mahanadi near Kurseong , south side, 1200 m, Oct. 6, 1978, C. Besuchet and I. Löbl ( MHNG PBI_OON 12672 ).

ETYMOLOGY: The specific name is a noun in apposition taken from the type locality.

DIAGNOSIS: Males of this species are similar to those of T. meghalaya by their relatively simple paraembolic projections on the male palp, but the bulb is narrow distally, gradually tapering to the area from which the embolus and accompanying elements arise (fig. 39F), and also by the presence of enlarged, stout setae in the epigastric area (figs. 37E–F, 38B). Females are recognizable by the long and tortuous posterior receptacle, with a broad anterior (ending) part, and by the shape of the anterior T-shaped sclerite, with thin, long, acute lateral projections (figs. 36H, 39E).

DESCRIPTION: Male (holotype, PBI_OON 12672). Total length 1.38. Cephalothorax: Carapace sides smooth; nonmarginal pars cephalica setae dark; marginal setae light, needlelike. Clypeus setae light, needlelike. Eyes on a black area, ALE largest, ALE oval, PLE oval; ALE–PLE separated by ALE radius to ALE diameter, PME separated by less than their radius. Sternum without radial furrows between coxae I–II, II–III, III–IV, microsculpture covering entire surface, lateral margins with indented extensions between coxae, orange; setae abundant, densest medially. Mouthparts: chelicerae orange; setae light. Labium orange. Endites orange, with the distal excavation with irregular margin. Abdomen: Book lung covers ovoid. Dorsal scutum orange. Epigastric scutum strongly protruding. Postepigastric scutum covering about 2/3 of abdominal length, orange. Spinneret scutum present, incomplete ring, slightly sclerotized. Dorsum setae dark. Posterior margin of epigastric protrusion with dark, thickened setae pointing anteriorly, two of them very large; this group of setae is flanked by other strong, erect setae (less thick) at sides and posteriorly, the latter also directed anteriorly (figs. 37E–F, 38B). Postepigastric area setae dark. Legs: Patella plus tibia I shorter than carapace. Leg spination (all spines longer than segment width): leg I: (The only known male has only the left leg, which seems to be anomalous), tibiae vp1-1- 1-1-0 (the first and the second stronger), vr1- 1-1-1-0, metatarsi v2-2-0; leg II: tibiae v2-2-2- 2-0, metatarsi v2-2-0. Trichobothria not examined. Genitalia: Epigastric region with sperm pore circular, situated in front of anterior spiracles, rebordered. Palp embolus straight, accompanied by two paraembolic, acute processes (one dorsal, another retrolateral); cymbium without stout setae, orange; distal part of the bulb with prolateral border bearing a subapical projection, covered marginally by setaelike structures (fig. 39F).

Female (paratype, PBI_OON 12672). Total length 1.44. As in male except as noted. Cephalothorax: Carapace nonmarginal pars cephalica setae in U-shaped row. PME touching for less than half their length. Palp without spines. Abdomen: Dorsal scutum covering full length of abdomen, orange. Spinneret scutum slightly sclerotized. Legs: Leg spination (all spines longer than segment width): leg I: femora pv0-0-1-0, tibiae v2-2-2- 2-0, metatarsi: v2-2-0; leg II: tibiae v2-2-2-2- 0, metatarsi v2-2-0. Trichobothria not examined. Genitalia: Ventral view: two dark areas (lateral extensions of the internal transverse bar) visible through the cuticle (fig. 36H). Posterior receptacle long and tortuous, with a broad anterior part (with a conspicuous, flattened lumen); anterior T-shaped element with thin, long, and acute lateral projections (fig. 39E).

OTHER MATERIAL EXAMINED: Same data as the types, Oct. 19, 1978, 1♀ ( MHNG PBI_OON 12848 ).

DISTRIBUTION: Known only from the type locality.

Figures

Fig. 36. Trilacuna mahanadi, new species, female (PBI_OON 12672). A. Habitus, dorsal view. B. Same, ventral view. C. Same, lateral view. D. Carapace, dorsal view. E. Same, ventral view. F. Same, lateral view. G. Same, anterior view. H. Epigastric area, ventral view.

Fig. 37. Trilacuna mahanadi, new species, male (PBI_OON 12672). A. Habitus, dorsal view. B. Same, ventral view. C. Same, lateral view. D. Carapace, dorsal view. E. Same, ventral view. F. Same, lateral view.

Fig. 38. Trilacuna mahanadi, new species, male (PBI_OON 12672). A. Carapace, anterior view. B. Abdomen, ventral view. C. Left palp, retrolateral view. D. Same, dorsal view. E. Same, prolateral view.

Fig. 39. Trilacuna spp., genitalia. A, B. Trilacuna meghalaya, new species, A. Female (PBI_OON 15404), internal genitalia, dorsal view. AP = apodeme; AS = anterior sclerite; PR = posterior receptacle; arrow = gland field. B. Male (PBI_OON 15338), left palp, retrolateral view. C, D. Trilacuna besucheti, new species. C. Female (PBI_OON 15393), internal genitalia, dorsal view. D. Male (PBI_OON 15005), left palp, prolateral view. E, F. Trilacuna mahanadi, new species. E. Female (PBI_OON 12848), internal genitalia, dorsal view. F. Male (PBI_OON 12672), left palp, prolateral view. GT = glandular tube.