Redescription and new data on the distribution of Scyloxes asiatica Dunin 1992 (Aranei: Scytodidae) from Tajikistan

2020·5.8 MB·English

by  Alexander A. Fomichev

Acta Arachnologica, 69 (1): 43–48, June 20, 2020
Redescription and new data on the distribution of Scyloxes asiatica Dunin 1992
(Aranei: Scytodidae) from Tajikistan
Alexander A. Fomichev1*& Yuri M. Marusik2–4
1Altai State University, Lenina Pr., 61, Barnaul, RF-656049, Russia. E-mail: [email protected]
2Institute for Biological Problems of the North, Portovaya Street 18, Magadan 685000, Russia.
3Department of Zoology & Entomology, University of the Free State, Bloemfontein 9300, South Africa.
4Zoological Museum, Biodiversity Unit, FI-20014 University of Turku, Finland
*Corresponding author
Abstract ―A poorly known species of spitting spider from a monotypic genus, Scyloxes asiatica Dunin
1992, is redescribed based on the types and newly collected material. The species is reported for the first time
outside of its type locality. Digital photographs and map of distribution records of S. asiatica are provided.
Key words ― Araneae, Central Asia, Hissar Mt. Range, new distribution records, spitting spiders
the Zoological Museum of Moscow State University, Mos-
Introduction
cow, Russia (ZMMU) and in the Institute of Systematics and
The family Scytodidae Blackwall 1864, known as spitting Ecology of Animals SB RAS, Novosibirsk, Russia (ISEA).
spiders, comprises 245 species assigned to five genera (WSC
2020). The family has a global distribution and is absent Abbreviations
only from the Boreal and Arctic zones of the Holarctic. Two Copulatory organs: Pg – pore glands, Rb – base of recep-
genera of Scytodidae are known from Central Asia, Scyloxes tacles, Re – receptacle, Rs – receptacle stem.
Dunin 1992 and Scytodes Latreille 1804 (Mikhailov 2013).
Redescription
The former is monotypic and known only from southwest-
ern Tajikistan (Dunin 1992). Since the original publication Scyloxes Dunin 1992
in Russian, this genus and species were never redescribed Scyloxes Dunin 1992: 79.
and were not reported outside of the type locality. During Type species. Scyloxes asiatica Dunin 1992.
the recent field trip to Tajikistan, we collected several speci- Diagnosis. The genus is similar to Stedocys Ono 1995
mens from different localities belonging to Scyloxes asiatica found in Southeast Asia, but differs from it by 14–57%
Dunin, 1992. We provide here an illustrated redescription of shorter legs in males and 20–60% shorter legs in females:
this peculiar species and genus based on type specimens and carapace/leg I ratio in the former and the latter is 1/6 vs.
newly collected material, and its new records. 1/7–1/14 in males and 1/4 vs. 1/5–1/10 in females, respec-
tively (cf. Figs 1–6 and figs 1, 3 in Suguro (2019)). Females
Material and Methods
of Scyloxes differ from those of Stedocys by the lack of
Specimens were photographed using an Olympus DP74 epigynal pouch (cf. Fig. 18 and fig. 3a in Wu et al. (2017)).
or Canon EOS 7D cameras attached to an Olympus SZX16 From another genus of Scytodidae occurring in the Palaearc-
stereomicroscope at the Altai State University and the Zo- tic, Scytodes Latreille 1804, Scyloxes can be distinguished
ological Museum, University of Turku. Photographs of by short cymbium, lacking an apical digitiform extension
macerated endogynes were prepared in a dish with glycerol. (cf. Figs 9–11, 13 and figs 6e–f in Özkütük et al. (2013)) in
Other photographs were prepared in a dish with cotton on males and by lacking of postgastral sulci (cf. Fig. 18 and figs
the bottom, filled with alcohol or alcohol-based hand sani- 6g–h in Özkütük et al. (2013)) in females.
tizer. Endogynes were cleared in a KOH/water solution until Description. Same as for the species.
soft tissues were dissolved. Digital images were montaged Composition. Monotypic.
using Helicon Focus software (https://www.photo-soft. Comments. Although Scyloxes habitually is similar to
ru/helicon-focus/). All measurements are in millimeters. Stedocys in having domed thoracic part, and males having
Lengths of leg I segments are given as: total (femur, patella, long palps with abrupt cymbium, it shares several charac-
tibia, metatarsus, tarsus). Material examined is deposited in ters with Loxosceles Heineken et Lowe 1832; the latter is
44 A. A. Fomichev & Y. M. Marusik
placed either in a separate family Loxoscelidae or in a sub- michev).
family Loxoscelinae in Sicariidae. Males of both Scyloxes Diagnosis. Same as for the genus.
and Loxosceles have swollen palpal tibia (character not Description. Male (holotype). Total length 6.7. Carapace:
present in Stedocys), receptacles originating from the base, 3.5 long, 2.65 wide. Coloration. Carapace yellow, with two
or basal part with a more sclerotized plate with numerous wide longitudinal gray stripes from lateral eyes to the posteri-
pore-glands (lacking in Stedocys); Scyloxes has two pairs of or part and with four thin longitudinal brown stripes medially.
receptacles and Loxosceles has one or more pairs (Gertsch Chelicerae yellow, with about 10 stridulating ridges. Sternum,
& Ennik 1983). Only one species of Stedocys, S. zhaoi Wu, labium and maxillae light yellow. Palps and legs light yellow.
Luo et Li. 2017, has two pairs of receptacles (other have Abdomen beige, with two longitudinal rows of indistinct gray
one, strongly sclerotized and lacking stalks) but lacking dis- spots in the posterior part. Spinnerets beige (Figs. 1–3). Leg I
tinct bases. This may indicate that either families are poorly measurements: 19.4 (5.8, 0.95, 6.1, 5.55, 1.0).
delimited or Scytodidae with Stedocys is not monophyletic. Palp as shown in Figs 9–13. Femur slender, almost 4
At the same time, differences between Stedocys and Scylox- times longer than wide, longer than tibia; patella as long
es are rather minor: 1) Stedocys has legs up to 2 times longer as cymbium and twice shorter that tibia. Tibia swollen, 2.3
(carapace/leg ratio), 2) Stedocys is a cave-dwelling genus, time wider than long; bulb (tegular part) globular, 1.3 times
while Scyloxes is found in open habitats, 3) Stedocys species shorter than cymbium; embolus long almost twice longer
build webs, while in Scyloxes webs were not reported, and than tegular part (bulb itself); embolus starting prolaterally,
4) Stedocys females do not possess epigynal pouch, but have apically acute, bent at an angle of 140°; sperm duct forms
postgastral sulci, and sclerotized median plates are lacking 1.25 coils (ca 450º), thick in retrolateral view, 3 times thin-
in Scyloxes, and have no stalks of receptacles. Both Scyloxes ner than bulb, duct strongly bent in anterior part of tegulum
and Stedocys differ considerably from other scytodid genera and strongly tapering (Fig. 12).
by having an abrupt cymbium lacking digitiform tip. At the Female (from Sambuli Village). Total length 6.5. Car-
same time, a similar cymbium is known for several other apace: 3.25 long, 2.65 wide. Coloration as in male, but
families of Scytodoidea, i.e. Drymusidae, Loxoscelidae longitudinal gray stripes running from lateral eyes are more
(currently a synonym of Sicariidae) and the more distant pronounced, median stripes absent. Sides of the carapace
Plectreuridae. with 3 pairs of gray radial stripes. Chelicerae as in male, but
It is worth noting that females of Stedocys zhaoi from stridulating ridges more developed (distinct). Abdomen
Thailand have endogyne very different from other conge- yellow-gray with 2 longitudinal rows of gray spots more
ners. Postgastral sulci is absent in this species, as well as pronounced than in male. Spinnerets light yellow (Figs.
posterior and/or anterior sclerotized plates, but has 2 pairs 4–7). Leg I measurements: 12.95 (3.8, 0.75, 3.8, 3.65, 0.95).
of receptacles with long stalks like in Scyloxes (character Endogyne and epigastric area as shown in Figs 14–19. Epi-
unknown in other Stedocys). Stedocys zhaoi has also unique gastric area with two brown spots, lacking in juvenile speci-
coiled tip of embolus unknown in other Scytodidae. In ad- mens (Figs. 18–19). Endogyne with 2 pairs of oval recepta-
dition, its type locality lies more than 1000 km apart from cles (Re) standing on long stem (Rs); receptacles and stems
other congeners. Most likely, Stedocys zhaoi should be covered evenly with pore glands (Pg); each pair of stems
placed in a separated genus, which is closer to Scyloxes than originates from hemispherical bases (Rb) densely covered
Stedocys. with pore glands on lateral sides.
Size variations. Female. Total length from 6.5–7.9. Cara-
Scyloxes asiatica Dunin 1992 pace: 3.25–3.3 long, 2.6–2.65 wide (n=2).
Figs 1–22. Biology. All specimens were collected in arid habitats
Scyloxes asiatica Dunin 1992: 79, f. 2, 7, 13–16 (♂♀). under stones, at the elevations from 400 to 980 m. No webs
were found when collecting specimens in 2019.
Material examined. Types: TAJIKISTAN: Khatlon Distribution. Hissar Mt. Range in southwestern Tajiki-
Region: holotype ♂ (ZMMU), Aruktau Mt. Range (west- stan. It is likely that this species occurs also in neighbouring
ern slope), Gandzhina Village, semidesert, 700–800 m, Uzbekistan.
7–12.04.1987 (S. L. Zonstein, A. Zor’kin); paratypes 4♀, Comments. Endogyne of this species is variable. Recep-
3juv. (ZMMU), together with the holotype. tacle stems can be long (3 times longer than receptacle) and
Other material: TAJIKISTAN: Khatlon Region: 1♀ thin (Figs. 14, 16) or can be short and thick (Figs. 15, 17).
(ISEA), Aruktau Mt. Range, 7 km SW from Sambuli Village, Specimen shown on Fig. 17 has stems with swollen anterior
37°45.602’N, 68°32.741’E, dry stony shiblyak shrubland part. Pore glands may be pronounced or indistinct (cf. Figs
with rocks, 660–980 m, 9.04.2019 (A. A. Fomichev); 1♀, 14 and 17). These variations were observed in specimens
1juv. (ISEA) Aruktau Mt. Range, 6 km ENE from Garavuti within the same population and seem without taxonomic
Village, 37°35.389’N, 68°31.654’E, stony desert, 400–630 value.
m, 7–8.04.2019 (A. A. Fomichev); 1juv. (ISEA) Ichkoran
Acknowledgements
Mt. Range, Teshiktosh Village, 37°08.612’N, 68°14.404’E,
stony desert with rocks, 450–550 m, 5–6.04.2019 (A. A. Fo- We wish to thank V. O. Shablya (Moscow, Russia) for organizing
Acta Arachnologica, 69 (1), June 2020 ⒸArachnological Society of Japan
Redescription of Scyloxes asiatica 45
Figs. 1–8. Habitus (1–6, 7), and chelicerae (8) of Scyloxes asiatica. 1–3, holotype male, dorsal, lateral and ventral; 4–7, female from Sambuli
Village, dorsal, lateral, ventral and frontal; 8, holotype male, ventral. Scale bars: 1–6 = 2 mm, 7 = 0.5 mm.
Acta Arachnologica, 69 (1), June 2020 ⒸArachnological Society of Japan
46 A. A. Fomichev & Y. M. Marusik
Figs. 9–13. Male palp of the holotype of Scyloxes asiatica. 9–11, terminal part, prolateral, anterior and retrolateral; 12, bulb, apical; 13, whole
palp, retrolateral. Scale bars: 9–12 = 0.1 mm, 13 = 0.2 mm.
Acta Arachnologica, 69 (1), June 2020 ⒸArachnological Society of Japan
Redescription of Scyloxes asiatica 47
Figs. 14–22. Scyloxes asiatica: endogyne (14–17), epigastric area (18–19), distribution records (20–21) and habitat (22). 14, from Sambuli
Village, dorsal; 15, from Garavuti Village; 16–17, paratypes, dorsal. 22, near Sambuli Village. Type locality, square; newly collected material,
circles. Frame on Fig. 20 refers to Fig. 21. Scale bars: 14–17, 19 = 0.1 mm, 18 = 0.2 mm. Pg, pore glands; Rb, base of receptacles; Re, receptacle;
Rs, receptacle stem.
the field trip to Tajikistan, during which part of the material treated in Gertsch, W. J. & Ennik, F. 1983. The spider genus Loxosceles in North
this paper was collected. Also, we thank S. Koponen and I. Sääksjärvi America, Central America, and the West Indies (Araneae, Loxos-
(Zoological Museum, University of Turku, Finland) for providing mu- celidae). Bulletin of the American Museum of Natural History, 175:
seum facilities. We thank K. G. Mikhailov (ZMMU, Russia) for allow- 264–360.
ing us the access to the holotype and paratypes of Scyloxes asiatica. Labarque, F. M., Grismado, C. J., Ramírez, M. J., Yan, H. M. & Gris-
Thanks go to E. A. Nepaeva (Barnaul) for her help in preparing the wold, C. E. 2009. The Southeast Asian genus Stedocys Ono, 1995
manuscript. The earlier draft of the manuscript was reviewed by S. L. (Araneae: Scytodidae): first descriptions of female genitalia and a
Zonstein (Tel-Aviv, Israel). We are grateful to the editor and reviewers new species from China. Zootaxa, 2297: 1–14.
for critical commenting of the manuscript. The English of the final Lehtinen, P. T. 1986. Evolution of the Scytodoidea. Proceedings of
draft was kindly checked by V. Fet (Hungtington, USA). the Ninth International Congress of Arachnology. Panama 1983:
149–157.
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