Perania annam, Peter J. Schwendinger & Ondřej Košulič, 2015

Peter J. Schwendinger & Ondřej Košulič, 2015, Two new species of armoured spiders from Vietnam and Cambodia (Araneae: Tetrablemmidae: Pacullinae), Revue suisse de Zoologie 122 (2), pp. 423-436 : 425-427

Perania annam sp. nov.

Figs 2 -3, 8 B

Holotype: MHNG; male; Vietnam, Lam Dong Province, Dalat ; collector unknown, don. J. Král Paratypes

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: 1 male, 1 female ( MHNG) and 1 male ( NMP); same data as for holotype.

Etymology: “ Annam ” is the former name of southern Vietnam. Noun in apposition.

Diagnosis: The new species differs from all congeners by the presence of conically elevated hair bases on tibia II of males and on metartarsus II of females. Males share with those of P. egregia Schwendinger, 2013 a very short cymbium (apex reduced) and a palpal organ with a thick embolus without marked transition between bulbus and base of embolus; P. annam sp. nov. males are distinguished from P. egregia males by the apex of the clypeal process being spade-shaped (with broadly rounded distal margin) rather than anvil-shaped (with slightly rounded or straight distal margin), by having a slightly more pronounced cymbial apex, a subterminal lamella which is pointed instead of rounded, and a longer embolic part ( Figs 3 A-E cf. Schwendinger, 2013: figs 9-10). The female of the new species differs from females of P. egregia by retaining a small preanal plate; its spermathecae have inclined instead of horizontal posterior margins; the central sclerite (pe = posterior extension of anterior collar in Fig. 3 F) in the dorsal wall of the vulva is much larger and thicker, with a widely rounded posterior margin (straight in P. egregia ) ( Fig. 3 F-H cf. Schwendinger, 2013: fig. 10 A-E).

Description of male (holotype): Colour (in alcohol) of sclerotised parts mostly dark brown, except for lighter patellae and tibiae I-II, patella to metatarsus III and patella to tarsus IV; membranous parts of opisthosoma very light brown. Clypeus with long, distally widened and flattened median process projecting foreward and slightly upward, occupying 34 % of carapace length, its distal margin broadly arched ( Fig. 2 A-B). Fovea indistinct and narrow, including two shallow pits ( Fig. 2 A). Total length 15.88. Carapace 8.73 long, 3.09 wide, its cephalic portion only slightly domed ( Fig. 2 B). Eye sizes and interdistances: PME 0.28 long, separated by 0.24; ALE 0.28 long; ALE-PLE 0.15; PLE 0.37 long, separated by 1.42. Labium 0.98 long, 1.27 wide. Sternum 3.53 long, 2.25 wide; sternal apophysis anvilshaped. Chelicerae without modifications; two small teeth distal to median lamina.

Palp 5.42 long (1.67 + 0.71 + 2.16 + 0.88). Cymbium ( Fig. 3 D) short, with indistinct retrodorsal lobe (apex). Palpal organ ( Fig. 3 B-E) strongly modified: bulbus and base of embolus of same thickness, without constriction between them; apex of embolus compressed and deeply split into a triangular, acutely pointed subterminal lamella and a longer and basally wider embolic part with a small, narrowly rounded tip.

Legs 3421. About 50 dark conical setal bases of various sizes prolaterally to ventrally on metatarsus I, about 30 shorter ones proventrally on tibia I; about 25 ones on metatarsus II and six on tibia II. All leg femora ventrally rugose (with wart-like hair bases); palpal femur essentially smooth. Paired leg claws with a row of 11-13 teeth on anteriorlegs, 8-9 onposteriors; unpairedlegclawswithone denticle. Leg I 22.54 long (6.96 + 2.45 + 6.76 + 4.61 + 1.76), leg II 17.90 long (5.25 + 1.96 + 5.10 + 4.02 + 1.57), leg III 13.43 long (4.02 + 1.47 + 3.43 + 3.24 + 1.27), leg IV 16.62 long (5.00+ 1.57 + 4.51 + 4.22 + 1.32).

Opisthosoma 7.16 long, 3.92 wide. Dorsal scutum ( Fig. 2 H) exceptionally narrow, 5.88 long, 2.99 wide, somewhat oval, quite smooth, its surface with only few indistinct elevations. Most lateral microplates flat, only a posterolateral one on each side of second band from above slightly elevated. Most microplates in bands on posterior side of opisthosoma closely packed, those in uppermost band largely fused into strap-like plate ( Fig. 2 H). Pulmonary plate 4.02 long, 3.33 wide; genital region flat. Anterior pair of ventrolateral plates largely free, only their posterior tips fused with margin of pulmonary plate. Postgenital plate 0.29 long, completely fused to posterior margin of pulmonary plate, both linked by a sclerotised suture. Preanal plate well developed, 0.78 long, 1.27 wide. Anal plate 1.23 long, 1.62 wide.

Description of female: As in male, except for the following. Total length 12.94. Carapace 5.29 long, 3.04 wide; cephalic portion more strongly domed than in male, with a short but distinct conical hump on clypeus occupying about 4 % of carapace length ( Fig. 2 E-F). PME 0.34 long, 0.21 apart; ALE 0.30 long; ALE-PLE 0.10; PLE 0.30 long, 1.57 apart. Fovea indistinct, with only one shallow pit. Labium 0.98 long, 1.76 wide. Sternum 3.04 long, 2.11 wide. Palp 4.26 long (1.27 + 0.59 + 0.98 + 1.42). Legs 3421; metatarsus I with about 25 conical setal bases of different sizes prolaterally and proventrally, tibia I with seven quite small ones prolaterally, metatarsus II with six very small ones prolaterally and proventrally; all conical setal bases weaker than those in males. Paired leg claws with a row of 9-14 teeth. Leg I about 17.5 long [5.20 + 1.82 + 5.10 + 3.73 + 1.7?(distal half missing)], leg II 14.80 long (4.31 + 1.62 + 4.12 + 3.28 + 1.47), leg III 11.32 long (3.28 + 1.27 + 2.84 + 2.75 + 1.18), leg IV 14.07 long (4.07 + 1.37 + 3.82 + 3.58 + 1.23).

Opisthosoma 7.65 long, 4.41 wide; several microplates in posterior half larger than others, slightly elevated and conical; microplates on posterior side of opisthosoma not forming strap-like horizontal plates. Dorsal scutum ( Fig. 2 G) 4.51 long, 2.55 wide, its anterior margin relatively wider and its surface with more pronounced elevations than in males. Anterior opisthosomal plate completely fragmented into microplates (nine of them slightly larger than others). Pulmonary plate 3.24 long, 3.04 wide. Preanal plate small, spindle-shaped, 0.15 long, 0.69 wide. Anal plate 1.23 long, 1.57 wide.

Vulva ( Fig. 3 F-H) with very long anterior collar, median zone of its dorsal and ventral walls distinctly lighter than lateral zones, posteriorly extended into a large and thick sclerite; transition between anterior collar and its posterior extensions weakly sclerotised and weakly pigmented, posterior margin of extension in dorsal wall widely rounded. Spermathecae and ventral wall of genital atrium lightly and uniformly pigmented, with a transparent zone between them. Spermathecae elliptical, with a distinct and wide median invagination in common anterior margin and with inclined posterior margins; anterolateral sides with relatively small porepatches on flat surface.

Variation: Carapace length in three males (one female) ranges 6.57-8.73 (5.29), carapace width 2.75-3.09 (3.04). In two males (including the holotype) the cleft between the subterminal lamella and the embolic part of the palpal organ is acute at its base ( Fig. 3 B), in the third male it is narrowly rounded ( Fig. 3 A). The number of conical hair bases on tibia II of males ranges 3-6. Variation in the shape of clypeus modifications of males see Fig. 2 A, C-D. All three males have most microplates in the uppermost band on the posterior side of the opisthosoma fused; one of them (a paratype) also has fused microplates in the second band from above. In all males the postgenital plate is relatively long (in comparison with males of other Perania spp.) and completely fused to the pulmonary plate.

Remarks: When we received the specimens, they all had their opisthosomata detached, widely cut open and the gonads removed for an examination of the chromosomes. This may have caused some minor deformation of the dorsal plates which may make them look slightly narrower than on intact specimens. The holotype has all legs of the left side missing, the allotype all legs on the right side. The only available female (the allotype) has its only remaining tarsus I incomplete. Since its tarsi II-IV are each one millimetre shorter than those of the male holotype, we assume that this is also the case in tarsus I. This puts its length at 1.7 mm, and the entire length of leg I at 17.5 mm.

Relationships: Males of P. annam sp. nov. and P. utara Schwendinger, 2013 (from Sumatra) share the conspicuous presence of conical setal bases on metatarsus II (not present in males of other congeners), but this is certainly a homoplasy. The strongly apomorphic palps of P. annam sp. nov. and P. egregia are phylogenetically much more informative than non-genital characters and clearly show that these two species are very closely related. This is also reflected in the female copulatory organs: the dorsal and ventral wall of their anterior collar each has a posterior extension that ends in a more or less pronounced sclerite, the ventral one partly covering the entrance to the spermathecae. Such structures were not observed in other congeners. Perania egregia occurs at the northeastern periphery of the previously know range of the genus and thus is – together with P. quadrifurcata Schwendinger, 2013 , found a bit further south (see Schwendinger, 2013: fig. 1) – the geographically closest conspecific species of P. annam sp. nov.

Distribution: This species is known only from Dalat (= Da Lat; exact locality unknown; approximately 11 ° 57 ’ N, 108 ° 26 ’ E), situated in the southern part of the Central Highlands of Vietnam, at about 1500 m altitude ( Fig. 1, inverted triangle). Further Perania species can be expected to occur in Vietnam, Cambodia and Laos.