Baiyuerius carcharus Wei & J. Liu, 2025

Wei, Mian, Zhu, Yang, Liu, Jie, Zhang, He & Liu, Fengjie, 2025, New species and new combinations of the spider genus Baiyuerius Zhao, B. Li & S. Q. Li, 2023 (Araneae, Agelenidae, Coelotinae), Zootaxa 5636 (3), pp. 401-442 : 431-435

publication ID	https://doi.org/10.11646/zootaxa.5636.3.1
publication LSID	lsid:zoobank.org:pub:1A564430-7BA5-4159-A595-3BF3DF2F2D7A
DOI	https://doi.org/10.5281/zenodo.15561641
persistent identifier	https://treatment.plazi.org/id/24487D50-B41E-FFEE-9B91-F995FC90F84E
treatment provided by	Plazi
scientific name	Baiyuerius carcharus Wei & J. Liu
status	sp. nov.

Treatment

Baiyuerius carcharus Wei & J. Liu sp. nov.

Figs 1E View FIGURE 1 , 27–30 View FIGURE 27 View FIGURE 28 View FIGURE 29 View FIGURE 30 , 35 View FIGURE 35

Type material. Holotype ♂ ( CBEE), CHINA: Guangxi Zhuang Autonomous Region, Guiping City , Guigang County, Xishan Mountain , 23.3997°N, 110.0553°E, elevation: 88 m, 13.V.2020, M. Wei leg. GoogleMaps ; Paratypes: 2♂♂, 5♀♀ ( CBEE), same data as holotype GoogleMaps .

Diagnosis. Males of Baiyuerius carcharus sp. nov. resemble those of B. shenzhen and B. zuojiang by 1) cymbial dorsal apophysis absent, and lateral tibial apophysis normal in shape ( Fig. 27C View FIGURE 27 ; fig. 6C in Zhao et al. 2023; fig. 6G in Luo et al. 2023); 2) process of dorsal margin of conductor triangular or sawblade-shaped ( Fig. 27B View FIGURE 27 ; fig. 6B in Zhao et al. 2023; fig. 6F in Luo et al. 2023); 3) dorsal apophysis of conductor extremely long, with rectangular tip ( Fig. 27D, E View FIGURE 27 ; figs 6B, C in Zhao et al. 2023; figs 6F, G in Luo et al. 2023); 4) embolic base wide, subequal to the width of tegular sclerite ( Fig. 27B View FIGURE 27 ; fig. 6B in Zhao et al. 2023; fig. 6F in Luo et al. 2023). But the new species can be distinguished from B. shenzhen and B. zuojiang by 1) lateral tibial apophysis pointed backward ( Fig. 27C View FIGURE 27 ) [vs. pointed upward in the latter (fig. 6C in Zhao et al. 2023; fig. 6G in Luo et al. 2023)]; 3) process of dorsal margin of conductor triangular from ventral view ( Fig. 25B View FIGURE 25 ) [vs. sawblade-shaped in the latter (fig. 6B in Zhao et al. 2023; fig. 6F in Luo et al. 2023)]. Females of B. carcharus sp. nov. resemble those of B. daxi by spermathecae fused with each other ( Fig. 29B View FIGURE 29 ; fig. 2B in Zhao et al. 2023). And the new species can be distinguished from B. daxi by 1) atrium completed ( Fig. 29A View FIGURE 29 ) [vs. separated into two rooms in B. daxi (fig. 2A in Zhao et al. 2023)]; 2) with one pair of hoods ( Fig. 29A View FIGURE 29 ) [vs. with two pairs in B. daxi (fig. 2A in Zhao et al. 2023)]; 3) distal part of blind sacs of copulatory duct flattened ( Fig. 29B View FIGURE 29 ) [vs. acuminate in B. daxi (fig. 2A in Zhao et al. 2023)].

Etymology. The specific name is derived from Greek word “carcharus ”, meaning serrated, referring to the serrated margin of the conductor; adjective.

Description. Male holotype ( Fig. 28 View FIGURE 28 ). Carapace black, cervical and radial grooves distinct. Cephalic region moderately raised, lateral margin with distinct furrows. Chelicerae robust, with three promarginal teeth and two postmarginal teeth, condyle red. Sternum longer than wide. Abdomen pale yellow, with chevron-shaped patterns, covered by blueish gray hairs. Leg with black femur, tibia, and metatarsus and red patella and tarsus, metatarsi and tarsi of the first and second legs with long and dense hairs. Total length 8.89. Carapace 5.00 long, 3.19 wide, cephalic region 2.40 wide. Abdomen 4.02 long, 2.85 wide. Eye size and interdistance: AME 0.18, ALE 0.22, PME 0.23, PLE 0.25; AME–AME 0.07, AME–ALE 0.13, AME–PME 0.12, ALE–PLE 0.06, PME–PME 0.05, PME–PLE 0.25. Leg measurements: I 13.42 (3.74, 1.42, 3.04, 3.34, 1.88), II 12.05 (3.37, 1.33, 2.53, 3.01, 1.81), III 9.91 (2.78, 1.22, 1.78, 2.69, 1.44), IV 13.11 (3.58, 1.43, 2.79, 3.64, 1.67).

Male palp ( Fig. 27 View FIGURE 27 ). Patellar apophysis thick and digitate. Retrolateral tibial apophysis subequal to 1/2 the length of tibia. Lateral tibial apophysis small, situated near the dorsal margin of tibia and pointed backward. Cymbial furrow extremely short, less than 1/5 the length of cymbium, triangular in shape. Conductor long, both of the ventral and dorsal margins serrated, process of dorsal margin of conductor triangular in shape, with a short and sharp dorsal apophysis. Dorsal apophysis of conductor strong, extremely extended, with membranous base and sclerotized rectangular tip, basal lamellar present. Tegular sclerite nearly right-trapezoid-shaped. Embolus filiform. Embolic base enlarged. Median apophysis small, strongly sclerotized.

Female paratype ( Fig. 30 View FIGURE 30 ). Same in colour and abdominal patterns as male. Chelicerae with three promarginal teeth and two postmarginal teeth. Metatarsi and tarsi of the first and second legs with normal hairs. Total length 13.83. Carapace 7.20 long, 4.31 wide, cephalic region 3.82 wide. Abdomen 7.18 long, 4.81 wide. Eye size and interdistance: AME 0.17, ALE 0.26, PME 0.24, PLE 0.26; AME–AME 0.16, AME–ALE 0.28, AME–PME 0.15, ALE–PLE 0.10, PME–PME 0.12, PME–PLE 0.39. Leg measurements: I 14.48 (4.30, 1.75, 3.23, 3.28, 1.92), II 12.67 (3.81, 1.70, 2.71, 2.78, 1.67), III 10.69 (3.45, 1.53, 1.77, 2.57, 1.37), IV 14.92 (4.68, 1.89, 3.00, 3.84, 1.51).

Epigyne ( Fig. 29A View FIGURE 29 ). Epigynal teeth absent. Atrium large, occupying 1/2 of the epigynal plate. Epigynal pocket large, anterior margin W-shaped and strongly sclerotized. Posterior epigynal sclerite strong. Hoods situated laterally of atrium. Copulatory opening situated centrally.

Internal genitalia ( Fig. 29B View FIGURE 29 ). Copulatory ducts short, with elongate but flat blind sacs extending laterally, distal part of blind sac flattened, pointed inward. Spermathecae small, nearly spherical, and fused with each other, spermathecal heads reduced, with membranous tips remaining on the distal ends of blind sacs. Fertilization ducts short, situated posteriorly.

Distribution: China (Guangxi Zhuang Autonomous Region).