Perania egregia, Schwendinger, 2013

Schwendinger, Peter J., 2013, A taxonomic revision of the spider genus Perania Thorell, 1890 (Araneae: Tetrablemmidae: Pacullinae) with the descriptions of eight new species, Revue suisse de Zoologie 120 (4), pp. 585-663 : 611-615

Perania egregia sp. n. Figs 9-11

HOLOTYPE: MHNG; Ƌ; Thailand, Phetchabun Province, Lom Sak District, Nam Nao National Park , rivulet near park headquarters (16°44’33”N, 101°34’13”E), 850 m; 24.XII.1994; leg. P. J. Schwendinger.

PARATYPES: MHNG; 1 Ƌ, 6 ♀ (one selected as “ allotype ”, not dissected) (collected 21.X.1993) and 2 Ƌ (collected 24.XII.1994); all from the type locality; leg. P. J. Schwendinger.

ETYMOLOGY: Latin adjective “egregius, -a, -um” (= outstanding, distinguished). The species epithet refers to the unusual palpal characters of males of this species.

DIAGNOSIS: Males different from those of all congeners by the unique male palp with a short truncate cymbium and a short thick palpal organ. Females similar to those of P. tumida sp. n., distinguished by tibia I and metatarsus I ventrally with conical setal bases and by vulva with longer anterior collar and rounded posterolater corners of spermathecae.

DESCRIPTION OF MALE (holotype): Colour (in alcohol) generally brown, carapace, chelicerae and ventral sclerites dark brown; membranous parts of opisthosoma light grey-brown. Clypeus with long, distally widened and flattened median process projecting foreward and slightly upward, occupying 27% of carapace length (Fig. 9A-B). Fovea indistinct and narrow. Total length 10.2. Carapace 5.6 long, 2.5 wide. Eye sizes and interdistances: PME 0.27 long, separated by 0.12; ALE 0.24 long; FIG. 9

Perania egregia sp. n. (A) Carapace of male holotype, dorsal view. (B) Same, lateral view. (C-E) Anterior portion of carapace of three male paratypes, dorsal view. (F) Anterior portion of carapace of female “ allotype ”, lateral view. (G) Same, dorsal view. (H-J) Anterior portion of carapace of three female paratypes, dorsal view. Scale line 1.0 mm.

ALE-PLE 0.07; PLE 0.25 long, separated by 1.02. Labium 0.7 long, 1.0 wide. Sternum 2.6 long, 1.8 wide. Chelicerae without modifications; with two teeth on anterior margin of fang furrow.

Palp 3.4 long (1.3+0.6+1.0+0.5). Cymbium (Fig. 10D, see also Fig. 10C for male paratype) short, with widely truncate, indistinctly bilobate apex (unlike in any other Perania species). Palpal organ strongly modified: bulbus and base of embolus of same thickness, without constriction but with only a pallid zone between them; apex of embolus deeply split: lobate, narrowly rounded subterminal dorsal lamella separated FIG. 10

Perania egregia sp. n. (A) Left palp of male paratype, proventral view. (B) Same, retrodorsal view. (C) Left cymbium and palpal organ of same male, dorsal view. (D) Left cymbium of holotype, retrolateral view. (E) Left palpal organ of holotype, proventral view. (F) Apex of embolus of holotype, retrodorsal view. Scale line 1.0 mm.

by a V-shaped invagination from widely triangular embolic part; a tiny tooth at base of invagination between both apical parts (Fig. 10E-F).

Legs 3421. About 25 dark conical setal bases of various sizes prolaterally to ventrally on metatarsus I, about 15 shorter ones proventrally on tibia I. Paired leg claws with a row of 9-12 teeth; unpaired leg claws with one denticle. Leg I 14.9 long (4.6+1.6+4.3+3.1+1.3), leg II 12.0 long (3.6+1.3+3.3+2.6+1.2), leg III 9.0 long (2.8+1.0+2.2+2.1+0.9), leg IV 11.9 long (3.6+1.1+3.1+3.0+1.1).

Opisthosoma 4.8 long, 3.2 wide. Dorsal scutum 4.1 long, 2.6 wide, somewhat oval, quite smooth, its surface with only few indistinct elevations. All lateral microscerites flat, those in bands on posterior side of opisthosoma closely packed but not fused into horizontal plates. Pulmonary plate 3.2 long, 2.8 wide; genital region flat. Anterior pair of ventrolateral plates completely free, their posterior tips only touching margin of pulmonary plate. Postgenital plate completely fused to posterior margin of pulmonary plate, both linked by a sclerotised suture. Preanal plate 0.4 long, 1.0 wide, somewhat elliptical. Anal plate 0.9 long, 1.2 wide.

DESCRIPTION OF FEMALE (“ allotype ”; not dissected): As in male, except for the following. Membranous parts of opisthosoma lighter, especially in anterior half. Total length 9.3. Carapace 4.3 long, 2.5 wide; “cephalic” portion domed, with a distinct conical hump on clypeus occupying about 6% of carapace length (Fig. 9F-G). PME 0.27 long, 0.15 apart; ALE 0.24 long; ALE-PLE 0.09; PLE 0.24 long, 1.26 apart. Labium 0.7 long, 1.0 wide. Sternum 2.4 long, 1.8 wide. Second tooth on anterior margin of cheliceral fang furrow indistinct. Palp 3.3 long (1.0+0.5+0.7+1.1). Legs 3241; tibia I with about 10 conical setal bases prolaterally, metatarsus I with about 20 larger ones prolaterally and proventrally, all of them weaker than in males. Paired leg claws with a row of 10-15 teeth. Leg I 12.6 long (3.9+1.3+3.4+2.7+1.3), leg II 10.6 long (3.2+1.2+2.8+2.3+1.1), leg III 8.3 long (2.6+0.9+2.0+1.9+0.9), leg IV 10.7 long (3.3+1.0+2.8+2.6+1.0).

Opisthosoma 5.4 long, 3.5 wide; microplates in posterior half (especially dorsally) larger than others, slightly elevated and wartlike, those on posterior side of opisthosoma close to each other but not forming strap-like horizontal plates. Dorsal scutum 3.5 long, 1.5 wide, its surface with slight elevations (as in males) plus irregular shallow furrows (mostly along margins) and low ridges. Anterior opisthosomal plate completely fragmented into microplates. Pulmonary plate 2.6 long, 2.4 wide; genital region slightly more elevated than in male, its posterior margin widely rounded. Preanal plate completely fragmented into microplates, three of them slightly wider than the others. Anal plate 1.2 long, 1.5 wide.

Vulva (of paratypes) with very long anterior collar, its median zone distinctly lighter than lateral zones. Spermathecae and ventral wall of genital atrium uniformly pigmented. Spermathecae elliptical, with a slight median invagination in common anterior margin; lateral sides with porepatches on flat surface (Fig. 11).

VARIATION: Carapace length in four males (six females) ranges 4.6-6.0 (4.3-4.5), carapace width 2.2-2.6 (2.4-2.6). In the holotype the tiny tooth in the invagination between the subterminal dorsal lamella and the embolic part of the palpal organ is distinct on both palps (Fig. 10E-F), in the male paratypes it is tiny and quite indistinct on one or both palps (Fig. 10A-B). For variation in the vulvae of two females see Fig. 11. For variation in the shape of clypeus modifications of males see Fig. 9A-E, of females see Fig. 9F-J. Two male paratypes have several fused microplates in the uppermost band on the posterior side of the opisthosoma. In all males the postgenital plate is completely fused to the pulmonary plate. In two female paratypes 2-3 microplates in the preanal region are laterally extended; in another female paratype the median microplate is distinctly larger than the nearby ones.

RELATIONSHIPS: The palp of P. egregia sp. n. males is strongly autapomorphic, but the distinct clypeal hump and the conical setal bases on tibia I and metatarsus I of females (both latter characters unusual for Perania females) and similar vulvae indicate that this species is closely related to P. tumida sp. n. and P. quadrifurcata sp. n.

DISTRIBUTION: Known only from the type locality in the northeaster region of

Thailand (Fig. 1, locality 15).

BIOLOGY: The spiders were found in typical webs built under overhanging edges of earth banks on both sides of a small stream in an evergreen gallery forest with bamboo stands. When collected, the spiders played dead, spread their legs (other spiders then usually retract their legs!) and remained motionless. One of the females

FIG. 11

Perania egregia sp. n., two female paratypes. (A, D) Vulva, dorsal view. (B, E) Same, ventral view. (C) Same, anterior view. Scale line 0.5 mm.

collected in late October built three globular egg sacs in captivity between mid- December and early January. These were suspended in the web and contained 19, 14 and 27 grey-brown eggs and spiderlings.