Siamspinops garoensis Kadam, Tripathi & Sankaran 2022, sp. nov.
Creators: name: Sankaran, Pradeep M.
name: Kadam, Gautam
name: Sudhikumar, Ambalaparambil Vasu
name: Tripathi, Rishikesh
Publisher: name: Zenodo
Year: 2022
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Arachnida
Araneae
Selenopidae
Siamspinops
Siamspinops garoensis

description: Siamspinops garoensis Kadam, Tripathi & Sankaran, 2022 sp. nov.
Figs 1–4, 8
Etymology. The specific epithet is an adjective and refers to the type locality of the new species.
Type material. Holotype: ♂ from INDIA: Meghalaya: North Garo Hills: Resu Haluapara (25°55.42′N, 90°35.97′E; 197 m a.s.l.), 05 April 2022, from tree trunk, by hand, G. Kadam (ZSI/ WGRC /I. R.-INV.20973). Paratypes: 1 ♀, same data as for the holotype; 1 ♀, same data as for the holotype except West Jaintia Hills: Raliang (25°30.41′N, 92°28.32′E; 1089 m a.s.l.), 08 April 2022 (ZSI/ WGRC /I. R.-INV.20974 & 20975).
Diagnosis. Siamspinops garoensis sp. nov. is most similar to Siamspinops formosensis (Kayashima, 1934) as both share a short, hook-shaped median apophysis, semi-circular posterior epigynal pockets, and M-shaped uterus externus, but can be distinguished by the following combination of characters: males by distally rounded ventral branch of retrolateral tibial apophysis (vs. distally narrow in S. formosensis), dorsal branch of retrolateral tibial apophysis broad along its entire length in ventral view (vs. distally narrow in S. formosensis) and conductor with sclerotised retrolateral apex ending at 3-o’ clock ventrally (vs. 4-o’ clock in S. formosensis) (compare Figs 2H, 4A with Yu et al. 2019: figs 9, 15); females by deep posteromedian excavation of epigyne (vs. less deep in S. formosensis) and copulatory ducts with 14 turns (vs. 9 turns in S. formosensis) (compare Figs 3H–I, 4C–E with Yu et al. 2019: figs 4–5, 12–13).
Description. Male (holotype, Figs 2A–F, colouration in alcohol): Carapace, eye region, clypeus, chelicerae, endites, labium yellowish brown; sternum, leg and palp segments, opisthosoma, spinnerets creamy-white; carapace, dorsal chelicerae, dorsal and lateral opisthosoma, leg and palp segments with olive green blotches and streaks. Carapace covered with scattered fine white hairs, with brownish streaks; thoracic margin with curved setae (Fig. 2B). Eyes on low tubercles, encircled with black pigment (Fig. 2C). Chelicerae significantly longer than those of female; promargin with four and retromargin with two teeth (Figs 2E–F). Sternum round, hirsute (Fig. 2D). Opisthosoma sub-oval, hirsute (Fig. 2A). All tarsi with well-developed claw tufts. Body length 8.64. Carapace 4.07 long, 4.70 wide. Opisthosoma 4.58 long, 3.94 wide. Eye sizes and interdistances: ALE 0.11, AME 0.21, PLE 0.23, PME 0.21; ALE–ALE 1.71, AME–ALE 0.49, AME–AME 0.17, PLE–PLE 2.09, PME–PLE 0.41, PME–PME 0.84. Clypeus height at AMEs 0.12, at ALEs 0.26. Length of chelicerae 1.82. Length of palp and legs: palp 4.71 [1.62, 0.66, 0.82, 1.61], I 17.01 [5.11, 1.91, 4.55, 3.88, 1.56], II 21.96 [7.02, 2.11, 6.05, 5.12, 1.66], III 20.19 [6.98, 1.79, 5.42, 4.53, 1.47], IV 16.87 [5.81, 1.64, 4.36, 3.77, 1.29]. Leg formula: 2341. Spination of palp: femur pld 1 plv 3 do 3 rlv 5, patella pl 1 pld 2 do 2, tibia pl 2 pld 3 do 2 rl 1 rld 2, tarsus/cymbium pl 2 do 2 rld 1; legs: femur I pl 2 do 3, II–IV do 3; patellae I–IV 0; tibia I plv 7 rlv 8, II plv 7 rlv 7, III–IV 0; metatarsus I plv 6 rlv 6, II plv 6 rlv 5, III rlv 2, IV 0; tarsi I–IV 0.
Palp (Figs 2G–J, 4A–B): ventral branch of retrolateral tibial apophysis small, distally rounded and spoonshaped (Figs 2H–I, 4A–B; vRTA); dorsal branch of retrolateral tibial apophysis large, laminate, 2x wider than ventral branch of retrolateral tibial apophysis (Figs 2H–J, 4A–B; dRTA). Cymbium rounded, with long marginal setae (Figs 2G, I–J). Tegulum nearly flat, rounded (Figs 2H, 4A–B; T). Median apophysis small, unbranched, hookshaped (Figs 2H–I, 4A–B; MA). Conductor T-shaped, with long, folded, sclerotised and pointed retrolateral apex (Figs 2H–I, 4A–B; C, arrow 1). Embolus filiform, originating retrolaterally at 3-o’ clock position (left palp in ventral view), encircling tegulum, with short and sclerotised embolic base, with chisel-shaped tip, with a slight constriction near the tip (Figs 2G–I, 4A–B; E, EB, arrow 2).
Female (paratype, Figs 1A, 3A–F, colouration in alcohol): General aspects essentially as in male except the following: habitus dull pinkish creamy-white with pale dark blotches and streaks; opisthosoma posteriorly with indistinct chevron pattern (Fig. 3A). Chelicerae comparatively short; promargin with three teeth, retromargin with two (Figs 3E–F). Body length 10.36. Carapace 3.84 long, 4.56 wide. Opisthosoma 6.52 long, 4.95 wide. Eye sizes and interdistances: ALE 0.10, AME 0.19, PLE 0.21, PME 0.19; ALE–ALE 1.72, AME–ALE 0.50, AME–AME 0.14, PLE–PLE 1.91, PME–PLE 0.26, PME–PME 0.82. Clypeus height at AMEs 0.12, at ALEs 0.21. Length of chelicerae 1.47. Length of palp and legs: palp 3.61 [1.09, 0.60, 0.70, 1.22], I 13.80 [4.18, 1.63, 3.74, 3.02, 1.23], II 12.76 [4.19, 1.29, 3.38, 2.73, 1.17], III 16.12 [5.74, 1.55, 4.35, 3.33, 1.15], IV 14.14 [5.05, 1.37, 3.59, 3.01, 1.12]. Leg formula: 3412. Spination of palp: femur pld 1 plv 3 do 3 rld 1, tarsus pl 2 pld 2 do 2 rl 2 rld 1; legs: tibia I plv 8 rlv 8, II plv 7 rlv 7, III–IV pld 1; metatarsus II plv 6 rlv 5, III–IV 0. Genitalia (Figs 3G–I, 4C–E): epigyne with posteromedian excavation (Figs 3G–I, 4C–E; arrow 3), with semi-circular posterior epigynal pockets having sclerotised triangular prolateral rims, retrolateral rims indistinct (Figs 3G–H, 4C; EP). Copulatory openings small, semi-circular, obliquely oriented, with sclerotised prolateral rims (Figs 3G–H, 4C; CO), enclosing a broad epigynal median field having wavy lateral margins (Figs 3G–H, 4C; MF). Copulatory ducts long, compact, convoluted with 14 turns (Figs 3I, 4D–E; CD). Spermathecae short, lying posteromedially (Fig. 4E; S). Proximal part of copulatory ducts, spermathecae and fertilization ducts covered by M-shaped, hyaline uterus externus (Figs 3I, 4D; UE). Accessory bulbs of spermathecae thick, anteriorly oriented (Figs 3I, 4D–E; AB). Fertilization ducts leaf-like, diverging (Fig. 4E; FD).
Variation. Female (n=2): body length 9.43–10.36. Second female specimen (Fig. 1B) shows variation in leg spination as follows: tibia I plv 7 rlv 8, II plv 7 rlv 8, metatarsus II plv 5 rlv 5.
Distribution. Known only from Meghalaya, India (Figs 1C–D, 8).
Remarks. First record of the genus from India.
description: Published as part of Sankaran, Pradeep M., Kadam, Gautam, Sudhikumar, Ambalaparambil Vasu & Tripathi, Rishikesh, 2022, First record of Siamspinops Dankittipakul & Corronca, 2009 from India, first description of the female of Makdiops shevaroyensis (Gravely, 1931), and a catalogue of Indian selenopid fauna (Araneae, Selenopidae), pp. 109-121 in Zootaxa 5194 (1) on pages 110-113, DOI: 10.11646/zootaxa.5194.1.6, http://zenodo.org/record/7142079