Bifidocoelotes quadratus, Liao & Wang & Yin & Xu, 2022

Liao, Rongrong, Wang, Ziwei, Yin, Haiqiang & Xu, Xiang, 2022, A review of the genus Bifidocoelotes Wang, 2002, with the description of three new species from China (Araneae, Agelenidae), Zootaxa 5222 (2), pp. 179-189 : 186

Bifidocoelotes quadratus sp. nov. (ḦNJȒDĦ)

Figures 6 , 7

Type material. Holotype female ( HNU606 ), China, Guangxi Zhuang Autonomous Region, Laibin City , Jinxiu Yao Autonomous County, Shengtang Mountain , 23°59.12'N, 110°8.23'E, 12 X, 2021, Ailan He, Jinxin Liu, Zongguang Huang, Xuemei Yang, Rongrong Liao, Yingli Wen, Zhao Ye, and Yang Liu leg.

Etymology. The specific epithet is a Latin adjective, referring to the shape of atrium.

Diagnosis. The female of this new species is different from those of all other Bifidocoelotes species (including the other two new species described in the present paper) by the extremely large atrium, while the atria of all other Bifidocoelotes species are smaller ( Fig. 1B ), usually reduced to a very small space ( Fig. 1A, D ) or a slit ( Fig. 1C, E ).

Description. Female: Total length 6.11, carapace 3.01 long, 1.84 wide, abdomen 2.90 long, 2.07 wide. Carapace pyriform, head region raised with broad anterior margin, thoracic region with yellowish lateral margins. Fovea brown, short, linear. Eye sizes and interdistances: AME 0.08, ALE 0.12, PME 0.12, PLE 0.13, AME–AME 0.04, AME–ALE 0.04, PME–PME 0.05, PME–PLE 0.13, ALE–PLE 0.07, AME–PME 0.11, ALE–ALE 0.34, PLE–PLE 0.59. MOA 0.34 long, anterior width 0.23, posterior width 0.33. Clypeus height 0.09. Chelicerae yellow-brown. Endite brown, longer than wide. Labium brown. Sternum yellow-brown, with sparse brown setae. Legs yellowbrown, with black annulations and some spines. Leg measurements: I 7.20 (2.00, 0.65, 1.73, 1.81, 1.01); II 5.05 (1.53, 0.48, 0.67, 1.60, 0.77); III 4.50 (1.62, 0.45, 0.96, 1.47, 1.08); IV 8.00 (2.20, 0.82, 1.68, 2.25, 1.05); leg formula IV, I, II, III. Abdomen oval, black dorsally, with five yellowish chevrons ( Fig. 6A ); yellowish ventrally, with scattered small dark patches. Spinnerets yellowish ( Fig. 6B ).

Epigyne ( Fig. 6C, D ): Atrium (At) extremely large, rectangular, located anteriorly. Epigynal tooth ( ET) long, originating from the middle of anterior margin of epigyne, with a strongly bifurcated terminal part (left branch broken in the holotype). Spermatheca (Sp) consisted of two parts: anterior part bean-shaped, posterior part extended horizontally, forming distinct lobules (seems to be the result of left and right bases fused). Copulatory ducts ( CD) long, strongly convoluted, situated between two bean-shaped parts of spermathecae. Spermathecal heads (SH) invisible in dorsal view, but visible in ventral view. Fertilization ducts ( FD) long and membranous, far from each other .

Male. Unknown.

Distribution. Known only from the type locality in China (Guangxi) ( Fig. 7 ).

Figures

FIGURE 1. The epigynes of six Bifidocoelotes spp., ventral view. A. Bifidocoelotes obscurus (after Zhou et al. 2017); B. Bifidocoelotes primus (after Zhou et al. 2017); C. Bifidocoelotes tsoi (after Wang et al. 2001); D. Bifidocoelotes mammiformis sp. nov.; E. Bifidocoelotes elongatus sp. nov.; F. Bifidocoelotes quadratus sp. nov.. Scale bar: 0.3 mm.

FIGURE 6. Bifidocoelotes quadratus sp. nov., holotype female. A. Habitus, dorsal view; B. Same, ventral view; C. Epigyne, ventral view; D. Same, dorsal view. Abbreviations: At, atrium; CD, copulatory duct; ET, epigynal tooth; FD, fertilization duct; SH, spermathecal head; Sp, spermatheca. Scale bars: A, B = 1 mm; C, D = 0.1 mm.

FIGURE 7. Collection localities for Bifidocoelotes in China. 1. B. mammiformis sp. nov.; 2. B. elongatus sp. nov.; 3. B. quadratus sp. nov.; 4. B. tsoi; 5. B. obscurus; 6. B. primus.