Thanatus arcticus Thorell, 1872

Lee, Sue Yeon, Yoo, Jung Sun & Kim, Chang Moon Jang and Seung Tae, 2023, Thanatus arcticus Thorell, 1872 (Araneae: Philodromidae) new to the Korean spider fauna, Journal of Species Research 12 (4), pp. 277-280 : 278-279

Thanatus arcticus Thorell, 1872 ( Fig. 1 )

ặǵḅNjĄŔ (ljḡ)

Thanatus arcticus Thorell, 1872: 157 ; Lenz, 1897: 76; Sørensen, 1898: 225; Fedotov, 1912: 463; Kulczyński, 1916: 24; Holm, 1958: 530; Dondale, Turnbull & Redner, 1964: 651; Holm, 1967: 81; Holm, 1968: 205; Hauge, 1976: 122; Dondale & Redner, 1978: 119; Marusik, 1991: 50; Logunov, 1996: 147; Almquist, 2006: 469; Tang & Wang, 2008: 78; Ono & Ban, 2009: 476; Pajunen, 2009: 86; Zhang, Peng & Zhang, 2022: 264; Marusik & Szűts, 2023: 95.

Thanatus mediocris Kulczyński, 1908: 66 ; Logunov, 1996: 135.

Thanatus lapponicus Jackson, 1932: 109 .

Thanatus kolymensis Marusik, 1991: 48 ; Marusik & Kovblyuk, 2011: 209.

Specimens examined. 1$, Mt. Chiaksan National Park, Hakgok-ri, Socho-myeon , Wonju-si , Gangwon-do , 4 May 2018 (Kim S. T. & Lee S.Y. leg.); 1$, Namchang Val- ley, Mt. Naejangsan National Park , Sinseong-ri, Bukhamyeon, Jangseong-gun, Jeollanam-do, 16 May 2018 (Kim S. T. & Lee S.Y. leg.) .

Description. Female. Total length 6.70. Carapace: 2.83 long, 2.62 wide. AER 0.78, PER 1.19. Chelicera: 0.92 long, 0.51 wide. Endite: 0.50 long, 0.41 wide. Labium: 0.27 long, 0.44 wide. Sternum: 1.50 long, 1.38 wide. Legs: I 7.94 (2.37, 1.16, 1.82, 1.47, 1.12)/ II 8.94 (2.68, 1.29, 2.08, 1.70 1.19)/ III 7.80 (2.43, 1.15, 1.86, 1.47, 0.89)/ IV 8.76 (2.65, 1.16, 1.99, 1.86, 1.10). Palp: 2.57 (0.79, 0.49, 0.53, -, 0.76). Epigynum 0.53 long/0.67 wide.

Carapace pear-shaped, brown, clothed densely with short, recumbent, and white hairs, lateral sides dark, cer- vical and radial furrows distinct and dark brown, trans- verse fovea slightly depressed, longer than wide ( Fig. 1A ). Eight eyes enclosed with a dark patch in two rows, AER slightly recurved and PER strongly recurved, median eyes slightly smaller than lateral eyes ( Fig. 1C ). Chelicera brown with two promarginal teeth (distal tooth larger than basal tooth). Endite pale brown, anterior margin truncated, longer than wide ( Fig. 1B ). Labium brown, wider than long ( Fig. 1B ). Sternum heart-shaped, brown with dark margin, convex, longer than wide, posterior tip round and not protruded between coxae IV, margin clothed sparsely with blackish brown recumbent bristles ( Fig. 1D ). Legs brown, robust and strongly developed, femora with two dark parallel lines on dorsal surface and two streaks on retrolateral surface, tibiae with a dark smudge proximal- ly, leg spination: I (femur 0-0-0-1-1-1-2d/0v; tibia 0-1d/ 1-2-2v; metatarsus 0d/2-2-0v; tarsus 0d/0v); II (femur 0-1-1d/0v; tibia 0-1d/2-2-2v; metatarsus 0d/2-2-0v; tarsus 0d/0v); III (femur 0-1-1d/0v; tibia 1-2d/2-2-2v; metatarsus 0-1-3d/2-2-1v; tarsus 0d/0v); IV (femur 0-1-1d/0v; tibia 0-2-2d/1-2-2v; metatarsus 1d/2-2-3v; tarsus 0d/0v), leg formula II-IV-I-III. Abdomen ovoid, pale grayish brown, clothed densely with short white hairs, longer than wide, dorsum with a blackish brown longitudinal spear-shaped cardiac pattern occupying anterior half, a pair of blackish brown short streaks posteriorly, clothed sparsely with long blackish brown recumbent bristles ( Fig. 1A ), venter pale grayish brown, clothed densely with short white and brown hairs ( Fig. 1B ). Epigynum ( Fig. 1E ): round and simple, sclerotized, wider than long; median septum broad anteriorly narrowing posteriorly; lateral guide pocket auricu- lar; anteromedial copulatory opening slit-shaped. Internal genitalia ( Fig. 1F, G ): spermatheca kidney-shaped and grooved posteriorly, almost contiguous each other; receptaculum spherical, approximately equal to receptaculum duct in length, protruded anteromesad.

Habitat. Mountainous mixed forest.

Distribution. Korea (new record), USA (Alaska), Canada, Greenland, Northern Europe, Russia (Europe to Far East), Kazakhstan, China, Japan.

Figures

Fig. 1. Thanatus arcticus Thorell, 1872, female: A. Habitus, dorsal view; B. Ditto, ventral view; C. Eye area from above; D. Sternum; E. Epigynum, ventral view; F. Internal genitalia, ventral view; G. Ditto, dorsal view (CO=copulatory opening, FD=fertilization duct, LP =lateral guide pocket, MS=median septum; R=receptaculum, S=spermatheca). Scale bars in mm.