Perania quadrifurcata, 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 : 615-621

Perania quadrifurcata sp. n. Figs 12-14, 36H, 37B

HOLOTYPE: MHNG, sample TH-02/01; Ƌ; Thailand, Kanchanaburi Province, Sai Yok District, Sai Yok Noi Waterfall (14°14'16”N, 99°03'28”E), 200 m; 5.-7.VII.2002; leg. P. J. Schwendinger.

PARATYPES: MHNG, sample TH-02/01; 4 Ƌ, 4 ♀ (one of them the “ allotype ”), 1 juv. Ƌ collected together with the holotype; leg. P. J. Schwendinger. – MHNG, sample TH-00/06; 3 Ƌ, 2 ♀; Kanchanaburi Province, Sangkhlaburi District, Daichongthong Waterfall (about 14°59’N, 98°36’E), 200 m; 10.XI.2000; leg. P. J. Schwendinger. – NMP; 3 Ƌ, 1 ♀; Phetchaburi Province, FIG. 12

Perania quadrifurcata sp. n. (A) Carapace of male holotype, dorsal view. (B) Same, lateral view. (C) Anterior portion of carapace of male paratype, dorsal view. (D) Same, lateral view. (E) Anterior portion of carapace of penultimate male, dorsal view. (F) Same, lateral view. (G) Anterior portion of carapace of female “ allotype ”, dorsal view. (H) Entire carapace of “ allotype ”, lateral view. Scale lines 1.0 mm (A-B; C-G; H).

Kaeng Krachan District, Kaeng Krachan National Park, Khao Phanoen Thung , orchid trail (12°53’12”N, 99°21’57”E), 880 m; 4.XII.2011; leg. O. Košulič. – NMP ; 1 Ƌ; Nakhon Ratchasima Province, Wang Nam Khiao District, Sakaerat Biosphere Reserve, Wang Nam Khiao Forestry Training Campus (14°29’44”N, 101°56’17”E), 280 m; 8.XI.2011; leg. O. Košulič.

ETYMOLOGY: Latin adjective “quadrifurcatus, -a, -um” (= 4-forked). The species name refers to the unique shape of the embolus, the apex of which is divided into four tips.

DIAGNOSIS: Similar to P. ferox sp. n. Males distinguished by longer clypeal process; five to seven (instead of only three) strap-like horizontal plates on posterior side of opisthosoma; apex of palpal organ with four tips: two long and slender upper FIG. 13

Perania quadrifurcata sp. n. (A) Left palp of holotype, proventral view. (B) Same, retrodorsal view. (C) Left cymbium of holotype, prolateral view. (D, F) Apex of embolus of two male paratypes from the type locality; proventral view. (E, G) Same, retrodorsal view. Scale line 1.0 mm.

tips (corresponding to subterminal lamella), and a long and slender pointed tip plus a short rounded lobe (corresponding to embolic part). Females distinguished from those of P. ferox sp. n. by the presence of conical setal bases ventrally on metatarsus I (in some females also on tibia I); vulva wider, spermathecae with a pair of posterolateral compartments and with shallow trenches on anterior and lateral sides, without oblique unpigmented bands on ventral surface.

DESCRIPTION OF MALE (holotype): Colour (in alcohol) of sclerotised parts mostly dark reddish brown, carapace even darker; membranous parts of opisthosoma light grey-orange. Clypeus with long, distally widened and flattened median process projecting foreward and slightly upward, occupying almost 30% of carapace length (Fig. 12A-B). Fovea indistinct and narrow. Total length 12.4. Carapace 6.8 long, 2.7 wide. Eye sizes and interdistances: PME 0.27 long, separated by 0.17; ALE 0.25 long; ALE-PLE 0.09; PLE 0.25 long, separated by 1.21. Labium 0.9 long, 1.1 wide. Sternum 3.0 long, 2.0 wide. Chelicerae without modifications; one distinct and one indistinct tooth on anterior margin of fang furrow.

Palp 3.8 long (1.2+0.6+1.1+0.9). Cymbium of typical shape (Fig. 13C). Bulbus globular; embolus with deeply divided apex carrying four tips: subterminal dorsal lamella split into two shallow, pointed upper tips bent dorsad, one being slightly thinner than the other; embolic part separated from subterminal lamella by a widely V-shaped invagination; embolic part split into a shallow, pointed sigmoid lower tip above a much shorter, deeper, rounded lobe, both of them directed distad (Fig. 13A-B).

Legs 3421. About 30 dark conical setal bases (Fig. 36H) proventrally and ventrally on metatarsus I, about 20 proventrally and ventrally in distal half of tibia I. Paired leg claws with a row of 11-16 teeth (decreasing in numbers from anterior to posterior legs); unpaired leg claws with one denticle. Leg I 19.0 long (5.8+2.0+5.8+3.9+1.5), leg II 14.9 long (4.4+1.6+4.2+3.4+1.3), leg III 11.1 long (3.4+1.3+2.9+2.4+1.1), leg IV 14.8 long (4.6+1.3+4.0+3.7+1.2).

Opisthosoma 5.9 long, 4.0 wide. Dorsal scutum 5.3 long, 3.4 wide, somewhat oval, its surface with low elevations. Posterior side of opisthosoma with five strap-like horizontal plates. Pulmonary plate 3.7 long, 2.8 wide; genital region flat. Anterior pair of ventrolateral plates completely free, not connected to pulmonary plate. Postgenital plate completely fused to posterior margin of pulmonary plate, with a sclerotised suture linking them. Preanal plate 0.5 long, 0.9 wide, quadrangular, its anterior margin widely arched, its posterior and lateral margins straight. Anal plate 1.0 long, 1.3 wide.

DESCRIPTION OF FEMALE (“ allotype ”; dissected): As in male, except for the following. Total length 7.5. Carapace 4.6 long, 2.7 wide; “cephalic” portion domed, with a short and basally wide, somewhat pointed hump on clypeus (Fig. 12G-H). PME 0.21 long, 0.24 apart; ALE 0.20 long; ALE-PLE 0.09; PLE 0.21 long, 1.41 apart. Labium 0.8 long, 1.1 wide. Sternum 2.7 long, 1.8 wide. Palp 3.1 long (0.7+0.5+0.8+1.1). Legs 32=41; tibia I with about 20 conical setal bases prolaterally and proventrally, metatarsus I with about 30 slightly larger ones in the same position, all of them smaller than in males. Leg I 15.1 long (4.5+1.6+4.3+3.3+1.4), leg II 12.8 long (3.8+1.4+3.5+2.9+1.2), leg III 9.9 long (3.0+1.1+2.4+2.4+1.0), leg IV 12.8 long (3.9+1.2+3.4+3.2+1.1). Paired leg claws with a row of 15 teeth on anterior legs, 7-10 on posterior legs.

Opisthosoma 5.9 long, 4.2 wide; microplates in posterior half of dorsal side distinctly elevated and conical, those on posterior side of opisthosoma less elevated, very close to each other but not forming strap-like horizontal plates. Dorsal scutum 2.7 long, 1.6 wide, with relief slightly higher than in male. Anterior opisthosomal plate completely fragmented into microplates. Pulmonary plate 2.8 long, 2.6 wide; genital region almost flat, its posterior margin more rounded than in male. Preanal plate completely fragmented into microplates. Anal plate 1.1 long, 1.3 wide.

Vulva (Fig. 14C) with short anterior collar not surpassing anterior margin of wide spermathecae. Spermathecae and ventral wall of genital atrium uniformly pigmented. Spermathecae largely fused in the middle, their common anterior margin indistinctly invaginated. Each posterolateral corner of spermathecae with a sac-like compartment distinctly separated from anterior portion of spermathecae. Narrow

FIG. 14

Perania quadrifurcata sp. n., females; paratype from the type locality (A-B), “ allotype ” (C), paratype from Daichongthong (D-E). (A) Vulva, dorsal view. (B-D) Same, ventral view. (E) Same, anterior view. Abbreviation: plc = posterolateral compartment of spermatheca. Scale line 0.5 mm.

marginal porepatches on slightly concave surface lying in shallow trenches (see Fig. 14E for paratype).

VARIATION: Carapace length in twelve males (seven females) ranges 4.9-6.8 (4.4-5.0), carapace width 2.5-2.9 (2.6-3.0). The clypeal process in males is usually long (Fig. 12A-B), only in one male from Sai Yok Noi (the type locality) it is short and apparently malformed (Fig. 12C-D). All females, except one from Daitchongthong, have a basally wide, conical, pointed hump on the clypeus (Fig. 12G-H). A very similar but in dorsal view more apically rounded hump is also present in a penultimate male (Fig. 12E-F). Females from Sai Yok have distinct conical setal bases ventrally on tibia I and metatarsus I; the two females from Daichongthong have only very indistinct ones on metatarsus I, none on tibia I; the female from Kaeng Krachan has none on leg I. In all males from Daitchongthong and in the holotype from Sai Yok the postgenital plate is anteriorly completely fused to the pulmonary plate, in three males from Sai Yok it is anteromedially separated by a membranous stripe, and in a fourth male (from Sai Yok) it is anteromedially and anterolaterally separated. The preanal plate is absent in the “ allotype ” (from Sai Yok), indistinctly developed in three females from Sai Yok, rudimentary but quite distinct in the two females from Daitchongthong. Two of the four vulvae examined have an indistinctly outlined, very lightly pigmented central area in the ventral wall between the spermathecae and the genital atrium (possibly homologous with the oblique unpigmented bands on the spermathecae of P. ferox sp. n.). All males possess five distinct (plus two rather less distinct) strap-like horizontal plates posteriorly on the opisthosoma.

RELATIONSHIPS: The very complex apex of the embolus of P. quadrifurcata sp. n. is unique and probably evolved by a subdivision of the two parts (subterminal lamella and embolic part) of a bifid apex. Within the nasuta -group only P. ferox sp. n. and P. egregia sp. n. (males of P. birmanica are unknown) also lack a lobate dorsal projection on the embolic part. Strong similarities in the vulvae of P. quadrifurcata sp. n., P. ferox sp. n. and the holotype of P. birmanica indicate a very close relationship between these three species.

DISTRIBUTION: Known from two localities (about 100 km apart) in Kanchanaburi Province and from one locality about 150 km further south in Phetchaburi Province, all in western central Thailand, as well as from one locality on the Khorat Plateau in northeastern Thailand (Fig. 1, localities 16-19). The latter locality (represented by a single male collected by O. Košulič) is about 300 km away from the type locality (which is also the closest of the other three localities) and needs to be confirmed by additional specimens.

BIOLOGY: This species lives in the central and northeastern regions of Thailand, which are seasonally dry. All spiders were collected in the lowlands, in semi-evegreen lowland forest (Kaeng Krachan), evergreen gallery forest near streams and waterfalls (Sai Yok Noi, Daitchongthong), and in mixed evergreen-deciduous forest (Sakaerat). Thus the habitats of this species are relatively humid and shaded. The spiders built irregular loose sheetwebs with a retreat in holes or cracks in earthbanks or limestone rocks covered by moss. In early July (at the type locality) two males were found at night courting in webs of females; one male was then newly moulted and had its last exuvia hanging in the web. Not longer afterwards a female produced an egg cluster in captivity and suspended it in the web as described for P. siamensis ( Schwendinger, 1994: 455-456) .

THE PERANIA CERASTES SPECIES GROUP

DIAGNOSIS: Similar to the robusta -group. Characterized by the presence of proximally swollen, strongly sigmoid setae on slightly raised bases on the ventral side of metarsus I (Fig. 36G) in both sexes. Fovea anteriorly slightly wider and deeper than posteriorly in both sexes. Females possessing vulvae with an entirely or partly pigmented ventral wall of the genital atrium; spermathecae with distinctly outlined porepatches extending only little onto the dorsal side of the vulva; posterior area of spermathecae unpigmented. Males with long clypeal process, either digitiform (in P. cerastes ) or hourglass-shaped with a strongly rounded distal margin in dorsal view (in P. coryne ); chelicerae unmodified (in P. cerastes ) or with a median-retrolateral cheliceral boss (in P. coryne ); embolus of male palpal organ with bifid apex, sub- terminal lamella smaller than embolic part. Anterior pair of ventrolateral plates in males completely or largely free. Femora of legs and palps in males granular.

SPECIES INCLUDED: Perania cerastes , P. coryne .

DISTRIBUTION: Peninsular Malaysia (Fig. 1, localities 20-24).