Otacilia papilla, Dankittipakul & Singtripop, 2014

Dankittipakul, Pakawin & Singtripop, Tippawan, 2014, New species and new records of the spider genus Otacilia Thorell, 1897 (Araneae, Corinnidae) from Southeast Asia, Revue suisse de Zoologie 121 (3), pp. 383-394 : 390-392

Otacilia papilla sp. n. Figs 24-27, 29-32

HOLOTYPE: ♀; Indonesia, Sumatra, West Sumatra Province, old secondary forest above Harau Canyon, north of Payakumbuh , 750 m; 7.VI.2006; leg. P.J. Schwendinger (MHNG, sample Sum-06/11).

DIAGNOSIS: Otacilia papilla sp. n. can be easily distinguished from its congeners by the large, triangular epigynal depression (Figs 25, 29), and by the presence of digitiform papillae on the multilocular spermathecae (Figs 27, 30-32).

RELATIONSHIP: The female of Otacilia papilla sp. n. resembles that of O. sinifera Deeleman-Reinhold, 2001 (RMNH, examined) in having several modified structures on the surface of spermathecae, but the new species is much smaller and lacks anterior membranous bursae.

ETYMOLOGY: The specific epithet refers to the digitiform papillae on the spermathecae of this species.

DESCRIPTION OF FEMALE (HOLOTYPE): Total length 3.4; prosoma 1.5 long, 1.4 wide; opisthosoma 1.9 long, 1.1 wide.

PROSOMA: Broadest between coxae II and III, narrowed in cephalic region in front of coxae I; in profile highest in front of fovea, gradually sloping posteriorly. Carapace yellow, without conspicuous markings. Sternum yellow, with distinctly dark brown margin, subovoid, as long as wide, devoid of distinctive projection between leg coxae. Labium wider than long, anterior margin slightly curved. Palpal coxae rectangular, with thin apical scopulae. Cheliceral fang slender, moderately long; two small teeth each on promarginal and retromarginal fang grooves; frontal surface with two short bristles.

Eyes: Eight eyes arranged in two rows, occupying almost entire attenuated cephalic region; both eye rows slightly recurved; eyes subequal in size; PME smallest, pale and circular, other eyes circled with black ring. Eye sizes and interdistances: AME 0.08, ALE 0.08, PME 0.06, PLE 0.08; AME-AME 0.11, AME-ALE 0.12, PME-PME 0.14, PME-PLE 0.12, ALE-PLE 0.08; MOQ 0.34 long, anterior width 0.25, posterior width 0.26.

Legs: Leg formula 4123. Measurements: leg I 7.8 (2.2, 2.9, 1.7, 1.0); leg II 6.2 (1.6, 2.4, 1.2, 1.0); leg III 4.6 (1.4, 1.3, 1.0, 0.9); leg IV 8.5 (2.2, 2.6, 2.2, 1.5). All leg segments pale yellow. Spination: anterior femora armed with two widely separated dorsal bristles; femora I and II with one elongated prolateral spine; tibia I and II with six pairs of ventral spines; metatarsus I and II with two pairs of ventral spines; femora III and IV lacking prolateral spines; other leg segments devoid of large spines.

Opisthosoma: Truncate, sparsely clothed with fine pubescence. Dorsal scutum absent. Dorsum green. Venter pale yellow, without markings.

Genitalia (Figs 24-27, 29-32): Epigynal region very lightly sclerotized, without clear margin delimiting it from epigastric area, medially with large and prominent inverted-triangular lobe (Figs 24, 29). Copulatory orifices circular (Figs 24, 29), hidden underneath narrow end of funnel-shaped epigynal depression (Figs 25, 29-30). Copulatory ducts thick-walled, ascending anteriorly (Figs 25, 30), then descending to posteriorly located spermathecae. Spermathecae consisting of 3-4 chambers (Figs 25, 30-32), each chamber provided with digitiform papilla of unknown function (Figs 25, 30-32). Fertilization ducts falciform, originating from anterior lobe of spermathecae (Figs 25, 30). Bursae absent.

MALE: Unknown.

Otacilia papilla sp. n., female holotype (29-32); O. parva, new female from Sumatra (33-34). (29) Internal genitalia, ventral view. (30, 33) Same, dorsal view. (31) Same as 30, different focus. (32) Papilla on spermathecal chamber, dorsal view [another papilla visible (but not in focus) on upper left wall of same chamber]. (34) Spermathecal appendage, dorsal view. Abbreviations: D, epigynal depression; CO, copulatory orifice; FD, fertilization duct; P, papilla ; S, spermatheca; SA, spermathecal appendage.

NATURAL HISTORY: The type material of O. papilla sp. n. was collected by sifting thick decomposing leaf litter and other organic humus in a rain forest.

DISTRIBUTION: Known only from the type locality in the Barisan Mountains of western Sumatra .