Arabelia xizang Mu & Zhang, 2022

Mu, Yannan & Zhang, Feng, 2022, First record of the genus Arabelia Bosselaers, 2009 from China, with description of one new species (Araneae, Liocranidae), Biodiversity Data Journal 10, pp. 85436-85436 : 85436

Arabelia xizang Mu & Zhang, 2022 sp. n.

Materials

Type status: Holotype. Occurrence: individualCount: 1; sex: male; lifeStage: adult; Taxon: scientificName: Arabelia xizang; order: Araneae ; family: Liocranidae ; genus: Arabelia ; Location : country: China; stateProvince: Xizang Autonomous Region ; county: Markam ; locality: between 3351-3352 kilometres of National Highway 318 ; verbatimElevation: 3127; verbatimLatitude: 29°44'19.18"N; verbatimLongitude: 98°49'33.57"E; Event : year: 2020; month: 7; day: 21; Record Level : institutionID: the Museum of Hebei University ; institutionCode: MHBU Type status: Paratype. Occurrence: individualCount: 4; sex: female; lifeStage: adult; Taxon: scientificName: Arabelia xizang; order: Araneae ; family: Liocranidae ; genus: Arabelia ; Location : country: China; stateProvince: Xizang Autonomous Region ; county: Markam ; locality: between 3351-3352 kilometres of National Highway 318 ; verbatimElevation: 3127; verbatimLatitude: 29°44'19.18"N; verbatimLongitude: 98°49'33.57"E; Event : year: 2020; month: 7; day: 21; Record Level : institutionID: the Museum of Hebei University ; institutionCode: MHBU

Description

Male (Holotype): total length 3.76, carapace 1.57 long, 1.42 wide (CW); abdomen 2.19 long, 1.35 wide. Eye sizes and interdistances: AME 0.09, ALE 0.11, PME 0.08, PLE 0.09; AME-AME 0.04, AME-ALE 0.01, ALE-ALE 0.23, PME-PME 0.11, PME-PLE 0.06, PLE-PLE 0.36, ALE-PLE 0.06. Eye area 0.51 wide (EAW), cephalic region 0.78 wide (CRW), EAW/CRW 0.65. CRW/CW 0.55. MOA 0.22 long, anterior width 0.22, posterior width 0.27. Clypeal height 0.09 (CH), CH/AME 1.00. Chelicerae with three promarginal (largest at middle) and two retromarginal teeth (Fig. 3 E). Labium 0.24 long, 0.27 wide. Sternum 0.97 long, 0.93 wide. Carapace nearly round, deep brown, with darker longitudinal markings either side of fovea. Fovea distinct, longitudinal. Abdomen grey, lacking dorsal scutum, covered with black hairs, two white patterns at middle part (Fig. 2 A-C). Measurement and spines of legs as in Tables 1 , 2 .

Palp as in Fig. 3 (A-D). Femur longer than tibia and cymbium, femoral apophysis absent, ventrally with low hump at distal part (Fig. 3 A-B). Tibia shorter than cymbium (about 0.6 times). RTA thin and short, hook-shaped (Fig. 3 B-D). Cymbium two times longer than wide. Bulb narrower than width of cymbium. Tegulum oval, tegular apophysis absent. Sperm duct long, tapering from retrolateral to prolateral before entering base of embolus (Fig. 3 D). Embolus thin and short, directed anteriorly. Conductor membranous, originating in middle of tegulum.

Female: One paratype total length 3.95, carapace 1.36 long, 1.24 wide (CW); abdomen 2.59 long, 1.50 wide. Eye sizes and interdistances: AME 0.08, ALE 0.09, PME 0.06, PLE 0.08; AME-AME 0.05, AME-ALE 0.01, ALE-ALE 0.20, PME-PME 0.09, PME-PLE 0.06, PLE-PLE 0.34, ALE-PLE 0.05. Eye area 0.44 wide (EAW), cephalic region 0.61 wide (CRW), EAW/CRW 0.72. CRW/CW 0.49. MOA 0.22 long, anterior width 0.19, posterior width 0.23. Clypeal height 0.07 (CH), CH/AME 0.88. Other characters as in male, except the slightly larger body size (Fig. 2 D-E). Measurement and spines of legs as in Tables 1 , 2 .

Epigyne as in Fig. 4 . Epigynal plate 1.3 times wider than long. MS wide. Semicircular hood located above MS (Fig. 4 A, C). Copulatory openings large, oblique, anteriorly, separated about two times MS width. Copulatory ducts short and thick. Small, globular ST2 located at middle parts, kidney-shaped ST1 posterior (Fig. 4 B). Fertilisation ducts downwards, located posteriorly of spermathecae (Fig. 4 B, D).

Diagnosis

This new species is similar to the type species A. pheidoleicomes Bosselaers, 2009 in having similar-shaped palp in the male, the position of copulatory openings and the presence of an anterior hood in the female. However, it can be distinguished from A. pheidoleicomes Bosselaers, 2009 by: 1) the hook-shaped RTA (vs. straight, compare Fig. 3 C and Fig. 15 in Bosmans 2011); 2) the slightly curved embolus(vs. straight, compare Fig. 3 D and Fig. 16 in Bosmans 2011), 3) a large, wide and sclerotised hood (vs. small, compare Fig. 4 A and Fig. 7F in Bosselaers 2009) and 4) the kidney-shaped spermathecae (vs. round, compare Fig. 4 B and Fig. 7E in Bosselaers 2009).

Etymology

The specific name is derived from the type locality; noun.

Distribution

Known only from the type locality (China: Xizang).

Notes

The spiders of this new species are found under stones on the side of roads (Fig. 1 A). Female matured about half a month earlier than male (Fig. 1 B). We collected the adult females and subadult male, the male description being based on the adult reared from the subadult.

According to Bosselaers (2009), the type species of Arabelia show clear myrmecophily, but we did not find ants or termites when collecting this new species under gravel. Moreover, there are also differences in the colour between A. pheidoleicomes and A. xizang sp. n. in the natural state and in alcohol. The former species has brown carapace, grey abdomen in the natural state and yellow carapace, white abdomen in alcohol, while the new species is black in the natural state and has brown carapace and grey abdomen in alcohol. However, due to its similar genital characters, we placed this new species in Arabelia .

Figures

Figure 1. Habitat and female of Arabelia xizang sp. nov .. A habitat; B living image (Photograph by Yannan Mu).

Figure 2. Habitus of Arabelia xizang sp. nov .. A Male (holotype), dorsal view; B same, ventral view; C same, abdomen dorsal view; D Female (paratype), dorsal view; E same, ventral view.

Figure 3. Male palp and chelicerae. A left palp, prolateral view; B same, retrolateral view; C Same, dorsal view; D same, ventral view; E chelicerae, retrolateral view. Abbreviations: C - conductor; E - embolus; PTA - prolateral tibial apophysis; RTA - retrolateral tibial apophysis; SD - sperm duct.

Figure 4. Female genitalia. A Epigyne, ventral view; B Vulva, dorsal view; C Epigyne, ventral view; D Vulva, dorsal view. (A, B: cleared in pancreatin solution; C, D: macerated in Holly Oil). Abbreviations: CO - copulatory opening; CD - copulatory duct; FD - fertilisation duct; H - hood; ST 1 - primary spermatheca, ST 2 - secondary spermatheca.