Troglocoelotes sinanensis Zhou & Zhao, 2023

Zhou, Guchun, YE, Ru-rui & Zhao, Zhe, 2023, A new troglobitic species of the genus Troglocoelotes Zhao & S. Li, 2019 (Araneae, Agelenidae, Coelotinae) from Guizhou, China, Biodiversity Data Journal 11, pp. 103265-103265 : 103265

Troglocoelotes sinanensis Zhou & Zhao, 2023 sp. nov.

Materials

Type status: Holotype. Occurrence: catalogNumber: GZTR-230102-1 ; individualCount: 1; sex: female; lifeStage: adult; occurrenceID: 121C5F31-FAE2-5F04-AF69-9DE147BA39B4; Taxon: kingdom: Animalia ; phylum: Arthropoda ; class: Arachnida ; order: Araneae ; family: Agelenidae ; genus: Troglocoelotes ; Location : continent: Asia ; country: China; countryCode: CN; stateProvince: Guizhou; county: Sinan ; locality: Sunjiaba Town , Gaofeng Village , Huangjin Cave ; verbatimElevation: 695m; verbatimLatitude: 27.9113°N; verbatimLongitude: 108.2895°E; Identification : identifiedBy: Guchou Zhou ; Event : samplingProtocol: by hand; year: 2023; month: 1; day: 2; habitat: cave; eventRemarks: cave darkness, 17℃, RH 93%; Record Level : institutionID: Taxidermy Museum of Gannan Normal University ; institutionCode: GNNU; collectionCode: Rurui Ye

Description

Female (holotype): Total length 6.92. Carapace 3.73 long, 2.38 wide. Cephalic region pale yellowish-brown with brown margin, thoracic region ivory. Cervical and radial furrows distinct and longitudinal fovea very long and aciculate. Abdomen 3.19 long, 2.15 wide; yellowish and covered with numerous fine hairs. Eyes strongly degenerated, reduced to white spots (Fig. 3 D). Clypeus height 0.31. Chelicerae basally light brown and inflated. Chelicerae teeth black. Chelicerae each with three promarginal teeth and two retromarginal teeth. Maxillae and labium brown. Sternum 1.86 long, 1.59 wide, covered with hairs of varying lengths. Leg yellowish without annular striations; femur with several fine hairs (Fig. 2 A), legs ventrally with numerous fine hairs (Fig. 2 B). Palp and legs measurements: palp 5.03 (2.34, 1.31, 1.38); leg I: 13.92 (3.42, 4.89, 3.38, 2.23); leg II: 12.88 (3.38, 4.50, 2.85, 2.15); leg III: 11.35 (2.88, 4.16, 2.96, 1.35); leg IV: 16.55 (3.73, 5.05, 5.31, 2.46).

Epigyne: Epigynal teeth fingernail-shaped (Fig. 3 A, B); copulatory distinct (Fig. 3 B); copulatory duct slender, curved before reaching ellipsoidal spermatheca (Fig. 3 C); spermatheca ellipsoidal with a sprout shape (Fig. 3 C); spermathecal head small (Fig. 3 C); fertilisation duct small and indistinct (Fig. 3 C).

Male: Unknown.

Diagnosis

The female of Troglocoelotes sinanensis sp. nov. resembles T. proximus (Chen, Zhu & Kim, 2008), but can be distinguished by the morphology of the spermathecae: 1) spermatheca ellipsoidal with a sprout shape in T. sinanensis sp. nov. (Fig. 3 C), vs. in a discoidal shape in T. proximus ( Chen et al. (2008), fig. 8); 2) upper half of spermathecae away from each other in T. sinanensis sp. nov. (Fig. 3 C), vs. close together in T. proximus ( Chen et al. (2008), fig. 9).

Etymology

The specific name refers to the type locality, adjective.

Distribution

Known only from the type locality in Guizhou, China (Fig. 4 ).

Taxon discussion

Huangjin Cave is a vertical cave that is very difficult for humans to explore, so the discovery of this new species was accidental. This species is the deepest subterranean species found in the genus to date. The degenerated eyes and the pale body of Troglocoelotes sinanensis sp. nov. shows that it is a species well-specialised to subterranean life. Cave adaptation not only causes troglomorphism (morphological adaptation), but also promotes reproductive isolation and speciation ( Cizauskas et al. 2022). Considering the karst topography of eastern Guizhou, many new species of Troglocoelotes are likely to be found in this area in the future.

Figures

Figure 2. Troglocoelotes sinanensis sp. nov., the habitus of holotype female. A Dorsal view; B Ventral view; C Lateral view. Scale bars: 2 mm (A-C).

Figure 3. Troglocoelotes sinanensis sp. nov., holotype female. A Epigyne, ventral view; B Same, ventral view; C Same, dorsal view; D Cephalothorax, frontal view. Abbreviations: A = atrium; ALEM = pale marks of anterior lateral eye; CD = copulatory duct; CO = copulatory opening; ET = epigynal tooth; FD = fertilisation duct; PLEM = pale marks of posterior lateral eye; PMA = posterior margin of atrium; S = spermatheca; SH = spermathecal head. Scale bars: 0.50 mm (A-C), 1 mm (D).

Figure 4. Distribution records of Troglocoelotes species from Guizhou Province, China. 1. T. banmenensis Zhao & Li, 2019; 2. T. proximus (Chen, Zhu & Kim, 2008); 3. T. qixianensis Zhao & Li, 2019; 4. T. sinanensis sp. nov.; 5. T. tortus (Chen, Zhu & Kim, 2008).