Coelotes nojimai, Okumura & Zhao, 2021

Okumura, Ken-ichi & Zhao, Zhe, 2021, A New Species of the Subfamily Coelotinae (Araneae: Agelenidae) from Shiga and Fukui Prefectures, Japan, Species Diversity 26, pp. 235-240 : 238-239

Subfamily Coelotinae F. O. Pickard-Cambridge, 1893 Coelotes nojimai sp. nov. [Japanese name: Ōmi-yachigumo] ( Figs 1 , 2, 3-1–3 -6, 4A–C)

Type specimens. Holotype: female (NSMT-Ar 20961), Japan: Sanami, Imazu Town, Takashima City , Shiga Prefecture, 35.4329°N 136.0094°E, 12 November 2020, K. Kumada leg. Paratypes: 1 male (NSMT-Ar 20962), 1 female (NSMT- Ar 20963), Aiba, Shin-asahi Town, Takashima City , Shiga Prefecture, 35.3845°N 136.0198°E, 26 November 2020, K . Kumada leg .

Other specimens examined. SHIGA PREF. — Ritto City: Arahari (1♂ 1♀, 8 October 2005. Y. Ihara leg.) . Higashi-omi City, Doki-cho (1♂, 22 March 2003. K. Nojima leg.) . Gamogun, Hino-cho, Kaigake (2♂ 1♀, 9 November 2004, K. Nojima leg.) . Nagahama City: Nishi-azai-cho, Yamakado (1♀, 11 October 2011, K. Kumada leg.); Kinomoto-cho, Kaneihara (1♀, 18 July 2020, N. Tsurusaki leg.) . FUKUI PREF. — Tsuruga City, Kashimagari, Nakaikemi (2♂, 20 March 2002, K. Kumada leg.) . Nanjo-gun, Minami-echizen-cho: Itadori (1♂, 17 April 2003, K. Kumada leg.); Furuki (1♂ 3♀, 6 November 2004) . Yoshida-gun, Eiheiji-cho, Johoji (1♂ 1♀, 6 November 2004, K. Nojima leg.) .

Distribution. Shiga and Fukui Prefectures, Japan ( Figs 3 , 5 ).

Etymology. The trivial name is dedicated to Mr. Koichi Nojima who collected and provided ten specimens of this new species.

Diagnosis. Coelotes nojimai sp. nov. resembles C. yodoensis and C. nagaraensis in body size and the form of the epigyne but can be distinguished by the form of the male palp and internal female genitalia ( Figs 3 , 4 ). In addition, no specimens having intermediate characteristics have been identified in the areas of boundary line for distribution of each species ( Fig. 3 ). The CO in the ventral view is large and extremely curved in C. nojimai sp. nov., while in C. yodoensis and C. nagaraensis it is small and only slightly curved, and the PA of C. nojimai sp. nov. is markedly shorter than that of C. nagaraensis . In the female specimens, the SP of the new species were slender and elongated in the longitudinal direction, while they were thick and short in C. yodoensis and C. nagaraensis and were greatly curved in C. yodoensis .

Description of female (holotype). Total length 7.2, carapace 3.6 long, 2.2 wide; abdomen 3.6 long, 2.4 wide; sternum 1.7 long, 1.4 wide. Eye sizes and interdistances: AME 0.10, ALE 0.15, PME 0.13, PLE 0.14; AME–AME 0.06, AME–ALE 0.06, PME–PME 0.09, PME–PLE 0.16, AME– PME 0.13, ALE–PLE 0.06. MOA; anterior width 0.26, posterior width 0.35, length 0.36. Leg measurements: I: 7.6 (2.3, 2.6, 1.7, 1.0); II: 6.6 (2.0, 2.2, 1.5, 0.9); III: 6.2 (1.8, 1.9, 1.6, 0.9); IV: 8.7 (2.4, 2.8, 2.4, 1.1).

Chericeral promargin with three teeth and retromargin with four teeth.

Coloration: carapace yellowish brown with gray radial flecks; sternum yellowish brown; chelicerae and maxillae blackish brown; labium brown; dorsum of abdomen grayish brown with chevrons; venter yellowish brown with irregular flecks; legs yellowish brown with ring flecks.

Epigyne and internal genitalia ( Figs 2C, D , 4B, C ): epigynal plate almost hexagonal, twice as wide as its length, with deep color on the periphery; epigynal teeth slightly thin and situated in the anterior portions of the epigyne; SP slen- der, anteroposteriorly elongated, and situated close to each other; spermathecal heads situated on the anterior portion of the SP; copulatory ducts broad, covering the lateral regions of the genitalia.

Description of male (paratype). Total length 6.3, carapace 3.3 long, 2.2 wide; abdomen 3.0 long, 1.8 wide; sternum 1.7 long, 1.5 wide. Eye sizes and interdistances: AME 0.09, ALE 0.15, PME 0.13, PLE 0.14; AME–AME 0.05, AME–ALE 0.05, PME–PME 0.10, PME–PLE 0.15, AME– PME 0.15, ALE–PLE 0.06. MOA; anterior width 0.23, posterior width 0.36, length 0.37. Leg measurements: I: 8.2 (2.4, 2.8, 2.0, 1.0); II: 7.2 (2.1, 2.2, 1.7, 1.2); III: 7.0 (1.9, 2.1, 2.0, 1.0); IV: 8.9 (2.1, 2.9, 2.8, 1.1).

Chericeral promargin with three teeth and retromargin with four teeth.

Coloration: almost same as that of the holotype.

Palp ( Figs 2A, B, 3-1–3 -6, 4A): PA short and pointed from ventral view, but rounded from lateral view; lateral tibial apophysis absent; RTA large and broad; cymbial furrow indistinct and about one-fifth of the cymbial length; CO large and crescent-shaped; small CO dorsal apophysis present; median apophysis slightly crooked and spoon-shaped at the tip; embolus flagelliform and short. There are slight variations such as small PA and slender CO in the specimens from Fukui prefecture ( Fig. 3-5, 3 -6).

Remark. Many Japanese species of the subfamily Coelotinae have been classified under the genus Coelotes . Howev- er, recent studies using genetic data in addition to detailed morphological investigations have shown that these species in fact comprise several heterogeneric groups ( Okumura et al. 2017; Zhao and Li 2017; Okumura 2020). All the species that are closely related to the new species described in this study are currently classified as Coelotes . Therefore, the new species has also been provisionally classified as Coelotes .

Figures

Fig. 1. Holotype female of Coelotes nojimai sp. nov., dorsal view. Scale bar: 1.0mm.

Fig. 2. Copulatory organs of Coelotes nojimai sp. nov. holotype, NSMT-Ar 20961 (C), paratypes, NSMT-Ar 20962 (A, B), NSMT-Ar 20963 (D). A: Male palp (left), ventral view; B: male palp (left), retrolateral view; C: epigyne, ventral view; D: internal female genitalia. Scale bars: 0.5mm. Abbreviations: CO, conductor; ET, epigynal tooth; FD, fertilization duct; MA, median apophysis; PA, patellar apophysis; RTA, reterolateral tibial apophysis; SH, spermathecal head; SP, spermatheca.

Fig. 3. Comparison of the male palp of three species inhabiting around Lake Biwa. Coelotes nojimai sp. nov. [1 paratype, NSMT-Ar 20962– 6], C. nagaraensis [7 (topotype)–12], and C. yodoensis [13 (topotype)–18]. The photo numbers correspond to the numbers indicating the collection localities on the map. Scale bars: 0.5mm.

Fig. 5. Distribution of Coelotes nojimai sp. nov. and two closely related species, C. nagaraensis and C. yodoensis, on Honshu Island, Japan.

Fig. 4. Comparison of the copulatory organs of Coelotes nojimai sp. nov. (holotype, NSMT-Ar 20961 and parataypes, NSMT-Ar 20962, 20963; A–C), C. nagaraensis (topotypes; D–F) and C. yodoensis (topotypes; G–I). A, D, G: Male palp, ventral view; B, E, H: epigyne, ventral view; C, F, I: internal female genitalia. Abbreviations:CO, conductor; PA, patellar apophysis; SP, spermatheca. Scale bars: 0.5 mm.