Amaurobius danba Lin & Li, 2024

Lu, Ying, Lin, Yejie & Li, Shuqiang, 2024, Two new species of Amaurobius C. L. Koch, 1837 (Araneae, Amaurobiidae) from Sichuan Province, China, Zootaxa 5397 (1), pp. 116-126 : 117-118

Amaurobius danba Lin & Li , sp. nov.

Figs 1, 2, 3, 7A, 8A–D, 9

Type material. Holotype: ♁ (IZCAS-Ar44738), China, Sichuan, Ganzi Tibetan Autonomous Prefecture, Geshizha Town , Danba Co., Daxue Vill., (30.88°N, 101.88°E), 30 VII 2004, Xiang Xu leg. Paratypes: 2♀ (IZCAS-Ar44739, Ar44740), same data as holotype .

Etymology. The specific name refers to the type locality and is a noun in apposition.

Diagnosis. Amaurobius danba sp. nov. resembles A. guangwushanensis Wang, Irfan, Zhou & Zhang, 2023 (cf. Figs 1, 2, 3, 7A, 8A–D and Wang et al. 2023: 308, figs 1A–E, 2A–G) in that the males have similar conductor and embolus ( Figs 1A, 2A), and the females have similar spermathecae ( Fig. 3B). However, this new species can be distinguished by the male median apophysis spatula shaped, distinctly excavated on prolateral side ( Fig. 1A, B; vs. median apophysis doorknob-like), and the retrolateral tibial apophysis triangular, apically curved in retrolateral view ( Figs 1B, 2A, B; vs. retrolateral tibial apophysis thumb-shaped), and the dorsal tibial apophysis wider ( Figs 1A, B, 2B; vs. dorsal tibial apophysis relatively narrow); females can be separated by the posterior margin of median lobe slight procurved ( Fig. 3A; vs. median lobe narrow, posterior margin slightly recurved), and the lateral lobes triangular, pointed ( Fig. 3A; vs. lateral lobes with round margin), and the copulatory ducts inconspicuous ( Fig. 3B; vs. copulatory ducts transverse, located between spermathecae).

Description. Male (holotype; Fig. 8A, B): Total length 9.8, carapace 5.0 long, 3.6 wide; abdomen 4.8 long, 3.1 wide. Eye sizes and interdistances: AME 0.13, ALE 0.20, PME 0.14, PLE 0.18; AME–AME 0.11, AME–ALE 0.30, PME–PME 0.32, PME–PLE 0.46, AME–PME 0.23, ALE–PLE 0.12. Leg measurements: I: 12.4 (3.5, 4.3, 3.0, 1.6); II: 11.5 (3.3, 4.1, 2.7, 1.4); III: 9.9 (2.8, 3.6, 2.4, 1.1); IV: 12.7 (3.6, 4.7, 3.1, 1.3).

Colouration (in alcohol). Carapace brown without flecks, sternum yellowish, chelicerae dark brown, maxillae and labium brown, dorsum of abdomen brownish with yellowish stripes in the anteromedian part, four pairs of chevrons in the posterior part, and venter brownish with white lines in both lateral sides, legs yellowish brown without ring flecks, spinnerets yellowish.

Chelicera. With 3 promarginal and 4 retromarginal teeth.

Palp ( Figs 1A, B, 2A, B). Two apophyses present in the lateral to dorsal portion of tibia: retrolateral tibial apophysis triangular, apically curved, dorsal tibial apophysis with two processes: dorsal process wide, margin undulated, mesal process triangle shaped. Bulb almost oval. Conductor membranous, partly fused with tegulum; median apophysis spatula shaped, distinctly excavated on prolateral side; embolus short and conglutinates with the tegulum.

Female (paratype; Fig. 8C, D): Total length 11.6, carapace 5.0 long, 3.8 wide; abdomen 6.6 long, 4.4 wide. Eye sizes and interdistances: AME 0.13, ALE 0.18, PME 0.15, PLE 0.15; AME–AME 0.16, AME–ALE 0.48, PME–PME 0.42, PME–PLE 0.74, AME–PME 0.21, ALE–PLE 0.23. Leg measurements: I: 10.9 (3.1, 4.1, 2.2, 1.5); II: 10.2 (2.9, 3.9, 2.1, 1.3); III: 11.2 (3.2, 4.4, 2.4, 1.2); IV: 8.4 (2.4, 3.2, 1.7, 1.1).

Chelicerae. With 4 promarginal and retromarginal teeth.

Colouration (in alcohol). Colour and somatic morphology as in male, except as noted. Carapace reddish-brown to black, sternum yellowish to brown, chelicerae black, maxillae and labium dark brown, dorsum of abdomen dark brown to white, legs brown, spinnerets brown.

Epigyne and internal genitalia ( Fig. 3A, B). Lateral lobes triangular, pointed and distant from each other; median lobe rectangular, slightly excavated medially on both anterior and posterior margins, wider than long. Spermathecae spherical and distant from each other, copulatory ducts inconspicuous, fertilization ducts elongate and distinct.

Distribution. China (Sichuan, type locality; Fig. 9).