Coelotes oxyacanthus, Okumura, 2013

Okumura, Ken-ichi, 2013, Seven New Species of Spiders of the Subfamily Coelotinae (Araneae: Agelenidae) from Kyushu, Japan, Species Diversity 18, pp. 87-97 : 92-93

Coelotes oxyacanthus sp. nov.

[Japanese name: Togeboso-yachigumo] ( Fig. 5A–D )

Material examined. Holotype. NSMT-Ar 9862, female,

Arikawa, Nakadori Island, Goto Islands , Nagasaki Prefecture (32°93.0′N, 129°04.3′E), 8 February 2009 .

Paratypes. NSMT-Ar 9863, 1 male, Arakawa, Nakadori Island, Goto Islands , Nagasaki Prefecture, 8 February 2009; NSMT-Ar 9864, 1 female, Mt . Ryukan, 120 m alt., Wakamatsu Island, Goto Islands , Nagasaki Prefecture, 7 February 2009 .

Non-type specimens. All the specimens were collected from the Goto Islands , Nagasaki Prefecture . Ohiraki, Hisaka Island : 1 male, 29 November 2008 . Mt . Ryukan, 120 m alt., Wakamatsu Island : 1 female, 7 February 2009 . Mt . Tetega, 150 m alt., Fukue Island : 1 female, 14 February 2009; 1 female, 8 November 2009 . Okunokoba, Fukue Island : 1 female, 10 January 2010 . Koumu, Kishikucho, Fukue Island : 1 male, 6 November 2010 . Mt . San-no, 320 m alt., Nakadori Island : 1 male, 24 January 2010 .

Diagnosis. Coelotes oxyacanthus sp. nov. resembles C. hiradoensis Okumura and Ono, 2006 (q.v.) in its small-sized body, having short cymbium, long embolus, and slender epigynal teeth. These two seem to be sister species, but the former can be distinguished from the latter by the following points. The conductor of the palpus is short and branched in C. oxyacanthus , but that of C. hiradoensis is elongated in the direction of the tip of the cymbium. The epigynal teeth on the anterior portion are distant from each other in C. oxyacanthus , but close together in C. hiradoensis .

Description. Male (paratype, NSMT-Ar 9863). Total length 6.2; carapace 3.2 long, 2.1 wide; abdomen 3.0 long, 2.0 wide; sternum 1.6 long, 1.3 wide. Eye sizes: AME 0.09, ALE 0.18, PME 0.13, PLE 0.13. Distances between eyes: AME–AME 0.04, AME–ALE 0.05, PME–PME 0.04, PME– PLE 0.13, AME–PME 0.09, ALE–PLE 0.04. MOA: anterior width 0.22, posterior width 0.30, length 0.31. Leg measurements: I, 8.1 (2.3, 2.9, 1.9, 1.0); II, 7.3 (2.1, 2.5, 1.7, 1.0); III, 6.7 (1.9, 2.1, 1.8, 0.9); IV, 9.2 (2.5, 3.0, 2.6, 1.1).

Cheliceral promargin with three teeth and retromargin with two.

Palpus ( Fig. 5A, B ): patellar apophysis bifurcate; LTA broad; RTA not sharp; cymbial furrow elongate, occupying two-thirds of cymbial length; anterior edge of conductor complexly branched; embolus long and slender, arising in 5-o’clock position of cymbium as viewed from ventral side.

Coloration: carapace yellowish brown; dorsum of abdomen grayish brown, with yellowish-brown chevrons; sternum yellowish brown; chelicerae, maxillae, and labium brown; legs yellowish brown, without ring flecks.

Female (holotype). Total length 7.5; carapace 3.5 long, 2.0 wide; abdomen 4.0 long, 2.8 wide; sternum 1.5 long, 1.3 wide. Eye sizes: AME 0.08, ALE 0.18, PME 0.14, PLE 0.13. Distances between eyes: AME–AME 0.04, AME–ALE 0.08, PME–PME 0.06, PME–PLE 0.15, AME–PME 0.10, ALE– PLE 0.05. MOA: anterior width 0.20, posterior width 0.34, length 0.32. Leg measurements: I, 7.2 (2.1, 2.6, 1.6, 0.9); II, 6.6 (1.9, 2.3, 1.5, 0.9); III, 5.7 (1.7, 1.9, 1.4, 0.7); IV, 8.2 (2.3, 2.7, 2.2, 1.0).

Cheliceral promargin with three teeth, and retromargin with three teeth on left and two on right.

Epigynum and endogynum ( Fig. 5C, D ): anterior portion M-shaped, with thin sclerotized frames on both sides; posterior portion blackish; epigynal teeth long, acute, widely separated; spermathecae situated in posterior portion of epigynum, distant from each other; copulatory ducts long and strongly convoluted.

Coloration almost same as that of male paratype.

Distribution. Goto Islands, Nagasaki Prefecture ( Fig. 6 ).

Etymology. The specific name is a compound noun in the nominative singular, derived from the Latin prefix oxy, “sharp, acute”, and acanthus, “spine”, referring to the long and acute epigynal teeth in the new species.

Remark. The genital structures in both sexes of the new species are dissimilar from those of the type species of the genus Coelotes . It is, nonetheless, placed in Coelotes because its three most closely related species, C. hiradoensis , C. sawadai , and C. taurus , are also classified in this genus ( Okumura and Ono 2006; Nishikawa 2009).

Figures

Fig. 5. A–D, Coelotes oxyacanthus sp. nov.; E–H, Draconarius verrucifer sp. nov. A–B, NSMT-Ar 9863, paratype, male; C–D, NSMT-Ar 9862, holotype, female; E–H, NSMT-Ar 9865, holotype, female. A, Male palpus, ventral view; B, same, retrolateral view; C, E, epigynum; D, F, internal female genitalia; G, ocular area, frontal view; H, left chelicera, ventral view.Scales: 0.5mm.

Fig. 6. Map of Kyushu, Japan, showing the distribution of Coelotes oxyacanthus sp. nov. Draconarius verrucifer sp. nov., D. dialeptus sp. nov., and C. hiradoensis Okumura and Ono, 2006, also showing geographical replacement of C. hiradoensis by C. oxyacanthus.