Perania harau, Schwendinger, Peter J., 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 : 628-632

Perania harau sp. n. Figs 19-20

HOLOTYPE: MHNG, sample Sum-06/17; Ƌ; Indonesia, Sumatra, West Sumatra Province, N of Payakumbuh , entrance of unnamed cave above Harau Canyon (0°06’25”S, 100°40’37”E), 700 m; 9.VI.2006; leg. P. J. Schwendinger.

PARATYPES: MHNG; 3 Ƌ and 4 ♀ collected together with the holotype . – MHNG, sample Sum-06/15; 1 Ƌ (mature 14.XI.2006); forest above Harau Canyon , near unnamed cave (type locality), 700 m; 9. VI.2006; leg. P. J. Schwendinger.

ETYMOLOGY: The specific epithet refers to the type locality. Name in apposition.

DIAGNOSIS: Similar to P. picea , distinguished by smaller size and wider anterior pit in fovea. Males distinguished by distinctly longer clypeal process; transition between bulbus and embolus rather V-shaped, with inner margins (facing each other) not parallel (U-shaped, with parallel inner margins in P. picea ); distal portion of embolus with a distinct subapical ventral lamella and a very indistinct subterminal lamella. Females with smaller, more thick-walled internal chambers in the ventral side of their spermathecae.

FIG. 19

Perania harau sp. n.; male holotype (A-B, G-J) and four male paratypes (C-F). (A) Carapace, dorsal view. (B) Same, lateral view. (C-F) Anterior portion of carapace, dorsal view. (G) Left palpal organ, ventral view. (H) Left cymbium and palpal organ, prolateral view. (I) Left palpal organ, distal view. (J) Distal portion of left palp, retrolateral view. Abbreviation: ep = embolic part of bifid apex of palpal organ), sal = subapical lamella, stl = subterminal lamella. Scale line 1.0 mm (A-F; G-J).

DESCRIPTION OF MALE (holotype): Colour (in alcohol) dark brown on carapace, chelicerae, palps, anterior legs and ventral sclerites, slightly lighter on posterior legs, opisthosomal sclerites and palpal organ; membranous parts of opisthosoma light greybrown. Clypeus with moderately long, digitiform median process occupying 13% of carapace length (Fig. 19A-B). Fovea distinct, its anterior portion a relatively wide round pit, its posterior portion a shallow longitudinal furrow. Total length 7.8. Carapace 4.0 long, 2.3 wide. Eye sizes and interdistances: PME 0.25 long, separated by 0.13; ALE 0.24 long; ALE-PLE 0.06; PLE 0.24 long, separated by 0.95. Labium 0.7 long, 0.9 wide. Sternum 2.3 long, 1.7 wide. Chelicerae without modifications; with two teeth on anterior fang furrow.

Palp 3.5 long (1.1+0.4+0.9+1.1). Cymbium (Fig. 19H, J) relatively long, with narrow apex. Palpal organ with somewhat V-shaped transition from bulbus to embolus, inner sides of both parts (facing each other) not parallel but at an acute angle (Fig. 19H, J); embolus long, fairly straight in proximal portion, sigmoid in distal portion; a distinct, white, triangular subapical lamella ventrally below shallow, hook-shaped apex; subterminal lamella of apex very indistinct (visible as a small crest in Fig. 19G) and distad-directed; embolic part of apex long, shallow, tapering and ventrad-directed (Fig. 19H-J).

Legs 3241. Eight quite large conical setal bases distributed over almost entire length of metatarsus I proventrally and ventrally, three over distal third of tibia I prolaterally. Paired leg claws with a row of 10-15 teeth; unpaired leg claws with one denticle. Leg I 15.9 long (4.8+1.5+5.2+3.1+1.3), leg II 12.8 long (3.9+1.2+3.8+2.7+1.2), leg III 10.0 long (3.1+1.0+2.5+2.4+1.0), leg IV 13.0 long (4.0+1.1+3.5+3.3+1.1).

Opisthosoma 3.9 long, 2.6 wide. Dorsal scutum 3.5 long, 2.4 wide, somewhat oval, posteriorly wider than anteriorly, its surface smooth. A few microplates on anterior side of opisthosoma (above anterior margin of pulmonary plate) elevated and obliquely pointed; all other microscerites flat and separated from each other. Pulmonary plate 2.6 long, 2.1 wide; genital region flat. Anterior pair of ventrolateral plates largely free, only their posterior tips fused with margin of pulmonary plate. Postgenital plate only laterally fused with pulmonary plate, medially separated by a distinct, angular membranous stripe. Preanal plate 0.2 long, 0.7 wide, with right margin rounded and left margin straight. Anal plate 0.8 long, 1.1 wide.

DESCRIPTION OF FEMALE (“ allotype ”; not dissected): As in male, except for the following. Colour in alcohol generally lighter (more strongly bleached), difference between anterior and posterior legs less pronounced. Total length 8.0. Carapace 3.8 long, 2.5 wide, “cephalic” portion more strongly elevated than in male, without modification of clypeus. PME 0.25 long, 0.20 apart; ALE 0.25 long; ALE-PLE 0.07; PLE 0.24 long, 1.15 apart. Labium 0.7 long, 1.0 wide. Sternum 2.5 long, 1.8 wide. Palp 3.7 long (1.1+0.5+0.8+1.3). Legs 3241; tibiae and metatarsi I-II without conical setal bases. Paired leg claws with a row of 9-15 teeth. Leg I 15.1 long (4.7+1.5+4.6+3.0+1.3), leg II 12.5 long (3.8+1.3+3.5+2.7+1.2), leg III 9.6 long (3.0+1.0+2.4+2.3+0.9), leg IV 12.6 long (3.9+1.1+3.3+3.1+1.2).

Opisthosoma 4.5 long, 3.2 wide. Anterior plate fragmented into microplates, two of them slightly larger then the rest. Elevated and obliquely pointed microplates on anterior side of opisthosoma smaller than in male. Dorsal scutum 3.5 long, 2.7 wide,

FIG. 20

Perania harau sp. n.; two female paratypes (A-B; C-D). (A) Vulva, dorsal view. (B, C) Same, ventral view. (D) Same, anterior view. Abbreviation: ic = internal chamber of spermatheca. Scale lines 0.5 mm (A-C; D).

its surface with a few indistinct ridges. Pulmonary plate 2.5 long, 2.3 wide; genital region bulged, flanked by several curved wrinkles; posterior margin slightly and very widely invaginated. Preanal plate fragmented into microplates, a few of them slightly larger than others. Anal plate 0.9 long, 1.1 wide.

Vulva (of paratypes, Fig. 20) with quite long, entirely pigmented ventral wall of genital atrium; anterior collar short, its widely rounded anterior margin only little surpassing anterior margin of spermathecae; spermathecae very wide, their common anterior margin almost straight, not or only indistinctly invaginated, their lateral sides bulged, without trenches; porepatches extending far onto dorsal side of spermathecae; a fairly small pair of eliptical internal chambers with thick, closed or laterally open walls in ventral wall of spermathecae.

VARIATION: Carapace length in five males (four females) ranges 4.0-4.2 (3.5-4.0), carapace width 2.3-2.4 (2.3-2.6). See Fig. 19A-F for variation in the shape of the clypeal processes of five males, Fig. 20 for variation in the vulvae of two females. In the holotype and one male paratype the anterior pair of ventrolateral opisthosomal plates lie so close to the lateral margin of the pulmonary plate that they look fused; in other males the separation is more visible. In three male paratypes the postgenital plate is reduced to a small isolated sclerite of variable shape behind the gonopore; in the fourth paratype and in the holotype it is a short wide sclerite medially separated from the posterior margin of the pulmonary plate and laterally fused to it (as shown in Fig. 27E-F for P. picea ). In all females examined the peanal plate is completely fragmented into microplates.

RELATIONSHIPS: The new species is most closely related to P. picea . Both have a very similar embolus with a small, tringular, distad-directed subterminal lamella and a long, shallow, tapering, sharply ventrad-bent embolic part, and a very long genital atrium. These are probably synapomorphies.

DISTRIBUTION: Known only from the type locality on Sumatra (Fig. 1, locality 26).

BIOLOGY: Most spiders examined were collected from typical webs between rocks and boulders and on the walls at the entrance (in the twilight zone) of an unnamed granite cave surrounded by rain forest. These spiders show no recognizable adaptations to cave-life. One spider was found outside the cave.