Phyxioschema roxana, Schwendinger & Zonstein, 2011

Schwendinger, Peter J. & Zonstein, Sergei L., 2011, A taxonomic revision of the genus Phyxioschema (Araneae, Dipluridae), II: species from Central Asia, Zootaxa 2815 (1), pp. 28-48 : 38-44

Phyxioschema roxana sp. n.

Figures 6–8F

Phyxioschema raddei Simon, 1889 : Charitonov 1969: 64–65 (in part; misidentification of females).

Material. UZBEKISTAN: Kughitang Mts. , canyon 3 km SW of Vandob, 1700 m, 37°42'N, 66°36'E, male holotype ( TAU) , 1 male paratype ( MHNG) , 1 female " allotype " ( TAU) , 1 female paratype ( MHNG) , leg. S. Zonstein, 30. V.1995.— Surkhandarya Region , Kughitang Range , Bagly-Dara [= Baglydara] Gorge, 1500– 1800 m, Juniperus forest, under stones, 2 female paratypes, 1 penultimate male, leg. S. Zonstein, 7. V.1984 ( TAU) .— Kashkadarya Region , W. Hissar Mt. Ridge, Ishkent [38°50'48''N, 66°57'38''E, ca. 1200 m] near Yakkabagh, Juniperus forest, 1350 m, 1 female paratype, leg. S. Zonstein, 6.IV.1989 ( TAU) .— Ishkent and surroundings, Yakkabagh district, Bukhara region, 2 female paratypes, 5 juvs., leg. D. M. Fedotov, 16.IV.– 3. V.1942 (n° 5506; PU) .— Ugunaksai [Ugunak gorge], Koka-Bulashkul' , Kuibyshev , Yakkabagh district, Bukharskaya, 1 juv., leg. D. M. Fedotov, 7.–14.VII.1942 (n° 5507; PU) .— Ishkent and surroundings, Yakkabagh district, Bukhara region, 2 female paratypes, 2 juv. males, leg. D. M. Fedotov, 16.IV.–3.V.1942 and 24.IV.1942 (on two labels; n° 5508; PU) .— Yakkabagh District , Bukhara Region, 2 female paratypes and 1 juv. male, leg. D. M. Fedotov, 1942 (n° 5509; PU) .— Ishkent and surroundings, Yakkabagh district, Bukhara region, 3 female paratypes, 4 juvs., leg. D. M. Fedotov, 25.–28.III.1942 (n° 5512; PU) .— Western part of Zeravshan Mts., Aman-Kutan Pass, 1700 m, 39°58'N, 66°54'E, 3 male paratypes, 1 female paratype, leg. A. Zyuzin, 12. VI.1991 ( TAU) .— Kishlaki Khtay i Kul' [villages Khtay and Kul', NE of Samarkand], 3 female paratypes, Kap. [Captain] Barstchevski, 1896 (n° 5514; PU) .

TAJIKISTAN: foothills of Hissar Mt. Ridge, Varzob [= Varsob] Valley , 1100 m, 8 km N Dushanbe, 38°40'N, 68°47'E, 2 male paratypes, leg. S. L. Zonstein, 25. V .2002 ( TAU) .

Etymology. The new species is named after the Bactrian wife of Alexander the Great. Name in apposition.

Diagnosis. Relatively large species with fairly stout legs. Different from P. raddei by males possessing an almost symmetrical ventral spur with narrow, rounded or only slightly bilobed apex on tibia II, only two (instead of three) ventral keels on metatarsus II, and no enlarged proximoventral spine on metatarsus I; females with stouter spermathecae carrying usually 3–4 (rarely 2 or 5) receptacles; lateral receptacle with a wide base (usually not constricted to a neck) and median receptacle with long, strongly convoluted stalks.

Description. MALE (holotype). Colour in alcohol: Carapace ( Fig. 6A ) light reddish brown, with dark brown stripes (most distinct behind eye group) radiating from fovea and forming reticulate areas above leg coxae and on anterior carapace margin, and forming a dark marginal patch above femur I, above femur II and above femora III–VI; eye mound black. Labium and maxillae light brown, with white anterior and prolateral zones, respectively. Sternum mostly grey-black (almost as dark as opisthosoma), with contrasting light reddish brown sigillae (including fused ones forming postlabial depression; Fig. 6B ). Legs (including ventral side of coxae) mostly light reddish brown; tibia to tarsus I and metatarsus to tarsus II darker; 2 light longitudinal dorsal stripes on all patellae and tibiae (less distinct on legs I and II); dorsal side of leg coxae and palps light yellowish brown. Intersegmental membranes of limbs and membrane between leg coxae and sternum with irregular patches of dark pigment. Opisthosoma mostly grey-black, without pattern; genital region and all booklung plates grey-brown, a pair of light brown longitudinal, posteriorly divergent stripes separating genital region from anterior pulmonary plates; spinnerets grey-black, mottled with light spots ventrally.

Body 12.7 long. Carapace ( Fig. 6A ) 5.6 long, 4.8 wide, oval, almost flat, covered with fine dark adpressed hairs (most straight, few slightly curved) and few stronger bristles on and in front of eye mound, in front of fovea and on posterior margin (there strongest). Eyes on low mound; eye group 0.56 long, anterior eye row procurved, 0.81 wide, posterior eye row straight, 0.96 wide ( Fig. 7B ). Eye diameters and interdistances: AME 0.18, ALE 0.32, PME 0.22, PLE 0.22; AME–AME 0.12, AME–ALE 0.06, PME–PME 0.36, PME–PLE 0.02. MOQ 0.38 long, 0.38 wide anteriorly, 0.67 posteriorly. Fovea pitlike, with 2 long foveal setae anterior to it.

Chelicerae weak, grooves with 9 prolateral teeth and 17 light medioproximal denticles. Maxillae 1.4 long, 0.9 wide, with pallid prolateral zone; anterior lobe indistinct, with fairly wide but indistinct serrula on ridge. Labium 0.3 long, 0.8 wide, anterior edge distinctly setose, followed by pallid zone with few setae; posterior part pigmented, with more setae. Sternum ( Fig. 6B ) 3.0 long, 2.4 wide, cordate, with deeply excavated postlabial sigilla (medially fused with each other and with the labiosternal suture) and 3 pairs of indistinct marginal sigilla.

Palps ( Fig. 7C–D ). Spination: tibia p1,v2, r1. 7+7 trichobothria in 2 rows on tibiae, over 10 (difficult to see) in a zig-zag row on tarsi. Palpal organ with oval base and quite long, tapering, almost straight embolus with slightly curved tip.

Legs 1=234. All tarsi pseudosegmented and densely armed with spines. Metatarsal preening combs absent. I: metatarsus with all ventral spines (apart from longer distal ones) of similar size, none of them enlarged; tibia distinctly incrassate (clearly wider than tibiae III and IV), ventrally flattened, with strong spines prolaterally, ventrally and retrolaterally ( Fig. 7F ); patella with row of 4 short, mostly sigmoid (the distal one rather curved than sigmoid) spines retroventrally (on one side followed by a straight spine on distoventral margin), without triangular projection on retrolateral margin ( Fig. 7E ); femur with relatively short and wide band of hooked spinules retrodorsally ( Fig. 6C ). II: metatarsus ventroproximally with 2 widely separated, rounded keels ( Fig. 7K–N ), the proventral one ( Figs. 6E , 7L ) somewhat triangular, more strongly elevated and ventrad-directed than the other, the retroventral one ( Fig. 7N ) widely rounded, less elevated and slightly more pointing sideward; tibia distinctly incrassate, band of elongate spinules on prolateral side straight, slightly inclined from longitudinal axis of tibia, not reaching beyond height of distal side of ventral spur ( Fig. 6E–F ); ventral spur of tibia apically not widened, apex slightly bilobed and carrying 2 megaspines on left leg (normal condition; Fig. 7G ), not bilobed and carrying 3 megaspines on right leg (variant form; Fig. 7H ); megaspines on left (normal) leg almost parallel to each other, the prolateral one slightly surpassing the retrolateral one ( Fig. 7G ), on right (variant) leg median megaspine longest ( Fig. 7H ); femur with a long and narrow band of hooked spinules proventrally ( Fig. 6D ). Spination: I: patella v4/5; tibia p2, v26/28; metatarsus p1/4, v24/26; tarsus v32/38. II: patella p2; tibia p2/4, v2/3 megaspines; metatarsus d3, p4, v11; tarsus v37/46. III: patella p4, r1/2; tibia d2, p2, r2, v6; metatarsus d6, p4, v13, r3; tarsus p3/4, v31/32. IV: patella p2, r1; tibia d1, p3, v7, r2; metatarsus d7/8, p3, v13, r1/2; tarsus p3, v22/24, r1. Trichobothria: 9+ 9 in 2 rows on tibiae; over 10 (difficult to see) in one row on metatarsi; over 10 (difficult to see) in one row on tarsi. Paired claws with 10–12 teeth in sigmoid row, unpaired claw with 5–7 sessile teeth. Palp and leg measurements: see Table 1.

Opisthosoma 6.5 long, 4.5 wide; quite densely covered with many fine light adpressed hairs (mostly in posterior part) interspersed with fewer fine dark hairs and long dark bristles with orange-brown sockets. Posterior median spinnerets 1.0 long; posterior lateral spinnerets 7.5 long (proximal article 2.1, median article 1.9, pseudosegmented distal article 3.5).

FEMALE (" allotype "). Colour as in the male, except for: dark stripes and patches on carapace less distinct; sternum only slightly darker than surrounding parts; chelicerae more reddish, medioproximal denticles in groove darker; legs lighter; opisthosoma dorsally in posterior half with 3 indistinct light patches forming incomplete chevrons.

Body 15.2 long. Carapace 6.5 long, 5.4 wide. Eye group ( Fig. 7A ) 0.56 long, anterior eye row 0.99 wide, posterior eye row 1.07 wide. Eye diameters and interdistances: AME 0.21, ALE 0.36, PME 0.25, PLE 0.24; AME–AME 0.12, AME–ALE 0.09, PME–PME 0.43, PME–PLE 0.03. MOQ 0.42 long, 0.41 wide anteriorly, 0.78 posteriorly.

Chelicerae stronger than in male, grooves with 9/10 prolateral teeth and 24/25 medioproximal denticles. Maxillae 2.1 long, 1.2 wide, serrula slightly wider than in males. Labium 0.6 long, 1.1 wide. Sternum 3.2 long, 2.7 wide.

Palps. Spination: patella p1; tibia p1, v7/9; tarsus p1, v25. 7+7 trichobothria on tibiae and about 10 on tarsi (difficult to see). Tarsal claw with 10/11 teeth.

Legs 21=34. All tarsi integral; tibiae I and II not incrassate. Spination: I: patella p1; tibia p1, v7; metatarsus v23/24; tarsus v29/30. II: patella p2; tibia p2, v5; metatarsus p3, v19/21; tarsus v34/35. III: patella p4, r1; tibia p2/3, d2, r2, v6/7; metatarsus p4, d4/5, r1/2, v17; tarsus p3/5, v30/31. IV: patella p1/2, r1; tibia p2, d1/2, r2, v6; metatarsus p4, d5, r2, v13/15; tarsus p3/5, v25/27. Trichobothria: 2 rows of 10–11 each on tibiae; about 10 (difficult to see) in one row on metatarsi and on tarsi. Paired claws with 10–12 teeth in sigmoid row, unpaired claw with 5–7 sessile teeth. Palp and leg measurements: see Table 1.

Opisthosoma 6.9 long, 4.8 wide. Posterior median spinnerets 1.2 long; posterior lateral spinnerets 8.0 long (proximal article 2.4, median article 2.0, pseudosegmented distal article 3.6).

Vulva ( Fig. 8D ) with moderately wide spermathecae distinctly inclined from each other anteriorly; each spermathecal trunk with 4/5 receptacles; base of lateral receptacle wide (not constricted), with complete sclerotisation only on ental side and broken sclerotisation on ectal side, head of lateral receptacle hemispherical, covered with several pores; median receptacle with a fairly long, strongly convoluted, completely sclerotised stalk and a bulbous head with pores; 2/3 secondary receptacles ranging from large, with strongly convoluted stalk (as in median receptacle), to small, with bent stalk.

Variation. Measurements of adult males (n=7) and of females with open genital orifices (n=18; in parentheses): body length 10.5–15.3 (8.0–20.3), carapace length 5.4–6.3 (3.3–7.9), width 4.5–5.4 (2.9–6.5).

All specimens from the villages of Khtay and Kul’ and from the Aman-Kutan pass, one female from Baglydara and one female from Ishkent have their sternum not or only indistinctly darker than the surrounding parts. In all other specimens the difference in colouration is pronounced.

Patella I of males has 4–5 sigmoid spines retroventrally and 1–2 weaker, curved spines or stiff bristles distoventrally. The holotype has three megaspines on the ventral tibial spur of its right leg II ( Fig. 7H ) and two megaspines on the left leg ( Fig. 7G ); all other males examined have only two megaspines (see Fig. 7I–J ). The ventral tibial spur is apically more ( Fig. 7J ) or less ( Fig. 7H ) distinctly bilobed.

The female from the Aman-Kutan pass ( Fig. 8A ) has fairly narrow spermathecae, only one secondary receptacle (small ones hidden on the ventral side may have been overlooked), and slightly constricted bases (necks) on the lateral receptacles. This is rather typical for P. raddei . However, since its median receptacles have long coiled stalks (typical for P. roxana sp. n.) and since it was collected together with males of P. roxana sp. n., we attribute this specimen to the new species. A similar, but slightly less atypical vulva was found in a female from Ishkent ( Fig. 8B ).

Relationships and taxonomic status. Phyxioschema roxana sp. n. appears most closely related to P. raddei . Both species share the presence of many strong spines on their legs (especially so on the tarsi), pigmented intersegmental leg membranes, an incrassate and ventrally flattened tibia I in males, and partly sclerotised lateral receptacular bases in females. Judging from dark colouration, similarities in the shape of the female copulatory organs and in their way of life, both species appear most closely related to P. erawan Schwendinger, 2009 , one of the Phyxioschema species from Thailand. Considering the unresolved taxonomic status of Afghanothele lindbergi and A. striatipes , it is possible that P. roxana sp. n. will be synonymised with one of these two nominal species.

Distribution and habitat. The new species is known from seven localities in southern Uzbekistan and from one locality in western Tajikistan (Fig. 1, localities n° 20, 23–27, 33). All specimens examined were collected at high altitudes (1100–1800 m). Charitonov (1969: 64) mentioned a juvenile female, which probably belongs to this species, from Guldara Kolkhoz, Ugunski District (southern Uzbekistan), between 1380 and 2400 m. It appears at present that P. roxana sp. n. has a relatively small geographical range and is restricted to high altitudes, whereas P. raddei is much more widespread and occupies a much larger vertical range.

Phenology. Mature males were collected at the end of May and in mid-June. Those collected at the earlier date have their cheliceral fangs not yet fully pigmented, which indicates that they moulted only a few days before.

Remarks. Charitonov (1969: 64, 65) reported on P. raddei specimens in his collection (deposited in the Perm State University). Our re-examination of this material shows that it is a mixture of P. raddei and P. roxana sp. n. One single female (without other specimens in the same vial) from the village of Khtay (n° 5511; PU) seemingly has a malformed or undeveloped vulva with distally wide spermathecal trunks, without lateral receptacles (not previously observed in Phyxioschema ) and short straight median receptacles. Its sternum is not clearly darker than the surrounding parts. This suggests that this single female belongs to P. raddei , however, another female from the villages of Khtay and Kul’ was clearly identified as P.roxana sp. n. Thus we cannot associate specimen n° 5511 with either of these species. It may belong to an undescribed species, but this is unlikely. Due to some unusually preservative (possibly absolute alcohol), the tissue of several specimens in Charitonov’s collection has become unusually tough (almost like leather). This makes it difficult to study the fine details of the vulvae and therefore these are not illustrated here. Nevertheless, the general structure of these vulvae is discernible in most cases.

Figures

FIGURE 6A–F. Phyxioschema roxana sp. n., male holotype. A. Carapace, dorsal view. B. Prosoma, ventral view. C. Left femur I, retrodorsal view. D. Left femur II, proventral view. E. Tibia and metatarsus II, prolateral view. F. Tibia II, prolateral view. All scale lines 1.0 mm.

FIGURE 7A–N. Phyxioschema roxana sp. n., female allotype (A), male holotype (B–H, K–N), male paratypes from the type locality (I) and from Aman-Kutan (J). A–B. Eye region, dorsal view (bristles on MOQ of holotype omitted). C. Left palp, ventral view. D. Left bulb, retrolateral view. E. Left patella I, retrolateral view. F. Left tibia I and distal part of patella I, ventral view. G. Left tibia II, ventral view. H–I. Right tibial spur, ventral view. J. Left tibial spur, ventral view. K. Left metatarsus II, distal view. L. Same, prolateral view. M. Same, ventral view. N. Same, retrolateral view. All scale lines 1.0 mm; C–D, H–N to same scale.

FIGURE 8A–H. Phyxioschema roxana sp. n., vulvae of six female paratypes (D = "allotype"), dorsal view (A–F); Phyxioschema sp., vulvae of two females (G–H). A. Aman-Kutan. B. Ishkent. C–D. Vandob (type locality). E–F. Baglydara. G–H. Islamabad. All scale lines 0.1 mm.