Dysdera bartang, Fomichev, 2024

Fomichev, Alexander A., 2024, New data on Dysderoidea (Arachnida: Araneae) of the Pamir Mountains, Tajikistan, Zootaxa 5496 (4), pp. 579-587 : 580

Dysdera bartang sp. n.

Figs 1–9 , 22–23 .

Type. Holotype ♂ ( ISEA, 001.9102), TAJIKISTAN, Gorno-Badakhshan Region, Rushan Mountain Range, 25 km E from Rushon Village (37°58’37.0”N 71°50’20.6”E), rocky-clayey cliff, in the web of Pholcus sp. , 2200–2300 m, 7–8 July 2023 (A.A. Fomichev & Y. V. Dyachkov).

Etymology. The specific epithet is derived from Bartang River, which runs through Rushon District of Gorno-Badakhshan Region, close to the type locality.

Diagnosis. In having the similar in shape distal division of bulb (DD) two times longer than the tegulum (Te) and the semi-elliptical crest (C), the male of D. bartang sp. n. is most similar to that of D. dushengi Lin et al. 2020 from eastern Kazakhstan and western China and to that of D. pamirica Dunin, 1992 from Tajikistan. It can be distinguished from both by the anterior edge of distal division of bulb reaching the sperm duct (SD) (vs. not reaching) (cf. Figs 7, 9 and Fig. 26 in Fomichev & Marusik (2021), figs 7, 9 in Dunin (1992)) and the crest separated from the distal tip of external side of the bulb by its length in retrolateral view (vs. crest reaching the distal tip of external side of the bulb in retrolateral view) (cf. Fig. 9 and fig. 43 in Fomichev & Marusik (2021), fig. 7 in Dunin (1992)). Additionally, the male of the new species differs from that of D. dushengi in having a triangular lateral sheet (L) with sclerotized base in anterior view (vs. elliptical, non-sclerotized) (cf. Fig. 6 and fig. 42 in Fomichev & Marusik (2021)). The male of D. bartang sp. n. can be distinguished from that of D. pamirica by the triangular posterior margin of the tegulum (vs. abrupt) (cf. Fig. 8 and fig. 8 in Dunin (1992)).

Description. Male. Total length 6.1. Carapace: 3.4 long, 2.5 wide. Chelicera: 1.6 long. Eyes: AME 0.16, PLE 0.14, PME 0.13. Colouration. Carapace red. Chelicerae and endites orange. Labium and sternum red. Coxae I–II orange, III–IV yellow. Palps and legs yellow-orange. Abdomen and spinnerets beige. Leg measurements: I: 2.55, 1.75, 2.45, 2.35, 0.65 (9.75); II: 2.6, 1.65, 2.35, 2.3, 0.6 (9.5); III: 2.15, 1.2, 1.6, 2.05, 0.6 (7.6); IV: 2.6, 1.45, 2.15, 2.65, 0.75 (9.6). Leg spination: III: Ti p2 v2; Mt p1 v4. IV: Fe d4; Mt p2 r2 v10.

Bulb as in Figs 6–9 . Length/width ratio 2.7. Posterior apophysis (P) square in prolateral view, circular in retrolateral one. Distal division of bulb (DD) with sclerites which differ in shape: semi-elliptical in retrolateral view crest (C), semi-oval in prolateral view ridge on the internal part of the internal sclerite (IS), and triangular in anterior view lateral sheet (L). Distal tip of the external side of the bulb rounded.

Female. Unknown.

Distribution. Known only from the type locality in West Pamir.

Comments. Dysdera pamirica , the species similar to D. bartang sp. n., was described by Dunin based on both sexes from Chil’dara Gorge in Peter I Range. This mountain range belongs to West Pamir, as well as the Rushan Range where the holotype of D. bartang sp. n. was collected. Dunin noted that D. pamirica is closely related to D. afghana Denis, 1958 from Afghanistan ( Dunin 1992). Dysdera afghana is known only from the female and immatures, which were collected in Pirzada and Paghman Towns, south-west of Kabul (Denis 1956; Deeleman-Reinhold & Deeleman 1988). All specimens from Pirzada are juveniles and may belong to a separate, yet undescribed species. Both localities, Pirzada and Paghman, are situated in the southern macroslope of the Hindu Kush Mt. Range. The distance between Paghman and the type locality of D. bartang sp. n. is about 460 km, and these areas are separated by the Hindu Kush Mts reaching heights of 5000 m a.s.l. In comparison, the distance between the type localities of D. pamirica and D. bartang sp. n. is 160 km within the same mountain system. Therefore, the possibility that D. bartang sp. n. would be conspecific with D. afghana is very low.

Figures

FIGURES 1–5. Habitus (1), prosoma (2–4) and palp (5) of male of Dysdera bartang sp. n. (ISEA, 001.9102) 1–2—dorsal; 3—lateral; 4—ventral; 5—retrolateral. Scale bars: 1 = 2 mm; 2–4 = 1 mm; 5 = 0.2 mm.

FIGURES 6–9. Left bulb of Dysdera bartang sp. n. (ISEA, 001.9102) 6—anterior; 7—prolateral; 8—posterior; 9—retrolateral. Scale bar: 0.2 mm. Abbreviations: C—crest, DD—distal division of the bulb, ES—external sclerite, IR—ridge in the internal part of the internal sclerite, IS—internal sclerite, L—lateral sheet, P—posterior apophysis, SD—sperm duct, Te—tegulum.

FIGURES 19–23. Live specimen of Segestria pamirica sp. n. (19), its tube-web embedded in crack of rock (20) and habitat in Ishkoshim Mt Range (21) and collecting localities of Dysdera bartang sp. n. and S. pamirica sp. n. (22–23). Square—D. bartang sp. n.; circle—S. pamirica sp. n. The frame on Fig. 23 refers to the content of Fig. 22. 21—courtesy of Y.V. Dyachkov.