Acroterius circinatus Irfan & Bashir & Peng 2021, gen. et sp. nov.
Creators: name: Irfan, Muhammad
name: Bashir, Shahida
name: Peng, Xianjin
Publisher: name: Zenodo
Year: 2021
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Arachnida
Araneae
Linyphiidae
Acroterius
Acroterius circinatus

description: Acroterius circinatus gen. et sp. nov.
urn:lsid:zoobank.org:act: 826A098B-3362-42BB-95F7-3E3E0C763F04
Figs 15–18, 39
Differential diagnosis
The new species resembles Acroterius brevis gen. et sp. nov. (Figs 6A–D, 7A–B, 8A–D) in having a long distal suprategular apophysis and radix with broad circular serrated part, which give rise to the embolus at its distal end in the male palp, parmula with socket on ventral surface and copulatory ducts forming a semicircular loop before joining the spermathecae in epigyne (Figs 15A–D, 16A–B, 17A–D); it can be distinguished by the median projection of the distal arm of paracymbium wider than long (Figs 15B, 16B), but longer than wide in A. brevis gen. et sp. nov. (Figs 6B, 7B). The embolus basally broad, disk-shaped, robust and almost touches the semicircular serrated part of the radix (Figs 15A–D, 16A–B), but stout, thread–like and pointing away from the semicircular serrated part of the radix in A. brevis gen. et sp. nov. (Figs 6A–D, 7A–B). Radical apophysis thumb-shaped, curved (Figs 15B, 16B), but somewhat triangular in A. brevis gen. et sp. nov. (Figs 6B, 7B). The spermathecae situated dorso– mesally (Fig. 17D), but situated dorso–laterally in A. brevis gen. et sp. nov. (Fig. 8D).
Etymology
The species name comes from the Latin adjective ‘ circinatus ’, meaning ‘circular’ and referring to the circinate-shaped copulatory ducts in the ventral view of the epigyne.
Type material
Holotype CHINA • ♂; Yunnan Province, Longyang County, Bawan Township, Sancha He, Luoshuidong area; 24.92597° N, 98.75806° E; alt. 2300 m; 3 Jun. 2005; Charles Griswold leg.; HNU-CGY137.
Paratypes (9 ♂♂, 5 ♀♀)
CHINA – Yunnan Province, Longyang County • 7 ♂♂; same collection data as for holotype; HNU-CGY137 • 2 ♂♂; Bawan Township, Sanchahe, Luoshuidong area; 24.94755° N, 98.75564° E; alt. 2300 m; 3 Jun. 2005; Heng-mei Yan, Ke-ji Guo and Hong-bin Liang leg.; HNU-GKJ039 • 3 ♀♀; Bawan Dist., Nankang Yakou; 24.83178° N, 98.76472° E; alt. 2180 m; 25 May 2005; Charles Griswold and D.H. Kavanaugh leg.; HNU-2005–029A • 2 ♀♀; Bawan Township, Dasheyao Yakou; 24.93167° N, 98.75368° E; alt. 2488 m; on top of mountain; 30 May 2005; Heng-mei Yan and Ke-ji Guo leg.; HNU-CGY32.
Description
Male (holotype)
MEASUREMENTS AND COLOUR. Total length: 3.25. Carapace 1.56 long, 1.24 wide, cephalic region strongly elevated, yellowish; fovea, cervical and radial grooves distinct; clypeus 0.41 high (Figs 18A–C); abdomen 1.69 long, 1.21 wide (Fig. 18A–C). Eye sizes and interdistances: AME 0.08, ALE 0.09, PME 0.08, PLE 0.09, AME–AME 0.04, PME–PME 0.05, AME–ALE 0.9, PME–PLE 0.12, ALE–ALE 0.44, PLE–PLE 0.48, ALE–PLE contiguous.
CHELICERAE. With five promarginal and five retromarginal teeth.
LENGTH OF LEGS. I = 6.57 (1.71, 2.03, 1.88, 0.95), II = 5.78 (1.62, 1.81, 1.51, 0.84), III = 4.43 (1.29, 1.33, 1.13, 0.68), IV = 5.63 (1.64, 1.68, 1.49, 0.82). Leg formula I–II–IV–III.
PALP (Figs 15A–D, 16A–B). Paracymbium highly sclerotized, distal part with three projections, lateral projection large, slightly curved, tongue-shaped with blunt end in ventral view; median projection wider than long; ventral projection sclerotized, small with blunt end, strongly overlapping subtegulum (Figs 15B, 16B); distal suprategular apophysis long, distal part curved and pointing towards tegulum (Figs 15A–D, 16A–B). Radical apophysis slightly curved with blunt end, protruding upward above base of embolus (Figs 15A–D, 16A–B); embolic membrane protruding above distal semicircular part, in prolateral view (Figs 15A, 16A). Embolus highly sclerotized, robust, disk-shaped, almost touching semicircular serrated part of radix with pointed end (Figs 15A–D, 16A–B).
Female (HNU-CGY137)
MEASUREMENTS AND COLOUR. Total length: 3.38. Carapace 1.42 long, 1.12 wide, yellowish; fovea, cervical and radial grooves distinct; clypeus 0.19 high (Fig. 18D–F); abdomen 1.96 long, 1.61 wide (Fig. 18D– F). Eye sizes and interdistances: AME 0.07, ALE 0.09, PME 0.09, PLE 0.09, AME–AME 0.05, PME– PME 0.06, AME–ALE 0.07, PME–PLE 0.11, ALE–ALE 0.45, PLE–PLE 0.51, ALE–PLE contiguous.
CHELICERAE. With six promarginal and seven retromarginal teeth; reteromarginal teeth gradually decrease in length towards the distal end.
LENGTH OF LEGS. I = 5.32 (1.37, 1.69, 1.32, 0.94), II = 4.75 (1.36, 1.42, 1.15, 0.82), III = 3.43 (1.04, 1.04, 0.79, 0.56), IV = 4.58 (1.26, 1.44, 1.12, 0.76). Leg formula I–II–IV–III.
EPIGYNE. Parmula 0.55 long, 0.24 wide at base (Fig. 17A–B); posterior projection of anterior wall of epigynal plate circular, forming circinate appearance (Fig. 17A–B). Spermathecae slender, situated dorso-mesally near median septum pointing toward lateral walls (Fig. 17D).
Distribution
China (Yunnan Province, Fig. 39).
description: Published as part of Irfan, Muhammad, Bashir, Shahida & Peng, Xianjin, 2021, Acroterius gen. nov. (Araneae: Linyphiidae: Linyphiinae) with twelve new species from Yunnan, China, pp. 1-53 in European Journal of Taxonomy 743 on pages 20-23, DOI: 10.5852/ejt.2021.743.1293, http://zenodo.org/record/4664312