Segestria pamirica, Fomichev, 2024

Fomichev, Alexander A., 2024, New data on Dysderoidea (Arachnida: Araneae) of the Pamir Mountains, Tajikistan, Zootaxa 5496 (4), pp. 579-587 : 582-585

Segestria pamirica sp. n.

Figs 10–23 .

Types. Holotype ♀ ( ISEA, 001.9103), 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, 2200–2300 m, 7–8 July 2023 (A.A. Fomichev & Y. V. Dyachkov); 3♀ ( ISEA, 001.9104), together with the holotype; 3♀ ( ZMMU), same region, Ishkoshim Mountain Range , 8 km NNW from Ishkoshim Village (36°47’43.6”N 71°34’11.5”E), rocks in the river canyon, 2500 m, 11–12 July 2023 (A.A. Fomichev & Y. V. Dyachkov).

Etymology. The specific epithet refers to the Pamir Mountains.

Diagnosis. The female of the new species differs from all other Central Asian species of Segestria , namely S. nekhaevae Fomichev & Marusik, 2020 , S. shtoppelae Fomichev & Marusik, 2020 and S. turkestanica Dunin, 1986 , in having the discoid ventral lobe of the anterior diverticulum (VL) situated on the same line with transverse bar of posterior diverticulum (TB) (vs. spherical ventral lobe of the anterior diverticulum located in front of transverse bar of posterior diverticulum) (cf. Figs 13–16 and figs 8B–E, G–J in Fomichev & Marusik (2020)). Additionally, S. pamirica sp. n. has the strongly developed pillar-shaped glands (PG) of the ventral lobe of the anterior diverticulum, which are poorly developed in S. shtoppelae and S. turkestanica . The new species can be further distinguished from S. nekhaevae by the absence of abdominal speckles (cf. Figs 10–11 and figs 3E, 4E in Fomichev & Marusik (2020)).

Description. Female (holotype). Total length 8.7. Carapace: 3.75 long, 2.35 wide. Colouration. Carapace light brown. Chelicerae and labium dark brown. Sternum and endites brown. Coxae and palps light brown. Legs: I–II yellow-brown, darker distally, III–IV yellow. Abdomen beige, dorsally with grey longitudinal stripe anteriorly and with 7 pairs of grey spots medially and posteriorly. Spinnerets beige. Leg measurements: I: 3.6, 1.35, 3.6, 2.95, 0.9 (12.4); II: 3.4, 1.35, 3.55, 2.9, 0.9 (12.1); III: 3.0, 1.25, 3.1, 2.75, 0.85 (10.95); IV: 3.3, 1.35, 3.6, 2.75, 1.0 (12.0). For leg spination see Table 1 .

Endogyne as in Figs 12–18 . Anterior diverticulum (AD) consists of two lobes: dorsal (DL) and ventral (VL). Dorsal lobe cylindrical, with widened tip. Ventral lobe discoid, wider than long, covered with pillar-shaped glands (PG). Transverse bar of posterior diverticulum (TB) bow-shaped, 2.7 times wider than ventral lobe of anterior diverticulum. Posterior diverticulum (PD) sac-like.

Male. Unknown.

Distribution. Known only from two localities in West Pamir.

Biology. Specimens were collected from cracks in rocky-clayey cliffs and rocks at night. Spiders were sitting in tube-webs embedded in cracks ( Figs 19–20 ). Specimens from Ishkoshim Mt Range were collected from the vertical rocks in a narrow river canyon. The river running directly at the base of the rocks provides relatively wet and cold conditions ( Fig. 21 ).

Comments. Segestria pamirica sp. n. collected at 36°N is the southernmost representative of the genus and family found in Central Asia. The new species extends the known range of the Segestriidae in Central Asia by about 3° to the south. In the past, S. nekhaevae was considered the southernmost species, being collected at 39°N in Hissar Mt Range in west Tajikistan ( Fomichev & Marusik 2020). The northernmost representative of the family in Central Asia is S. shtoppelae known from Dzhungarian Alatau Mts (44°N) in south-east Kazakhstan. In fact, Segestriidae are distributed even further north. In 2019, the author took part in a field trip to eastern Kazakhstan and collected several specimens from Kyzybel’tau Mts (47°N). Unfortunately, these specimens turned out to be juveniles. Thus, the latitudinal range of Segestriidae in Central Asia reaches 11° and covers almost the entire region from the north to the south.

Figures

FIGURES 10–18. Female habitus (10–11), endogyne (12) and anterior diverticulum (13–18) of Segestria pamirica sp. n. 10–13, 15, 17—holotype from Rushan Mt Range (ISEA, 001.9103); 14, 16, 18—paratype from Ishkoshim Mt Range (ZMMU). 10, 12, 17–18—dorsal; 11, 13–14—ventral; 15–16—lateral. Scale bars: 10–11—2 mm; 12–18—0.2 mm. Abbreviations: AD— anterior diverticulum, DL—dorsal lobe of anterior diverticulum, PD—posterior diverticulum, PG—pillar-shaped glands, TB— transverse bar of posterior diverticulum, VL—ventral lobe of anterior diverticulum.

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.