Cladothela bicolor Suzuki, 2022

Suzuki, Yuya & Tatsuta, Haruki, 2022, Two New Species of Ground Spiders (Araneae: Gnaphosidae) from Okinawa Islands, Japan, Species Diversity 27 (2), pp. 319-328 : 320-323

Cladothela bicolor Suzuki , sp. nov.

[New Japanese Name: Himune-washigumo] ( Figs 1–3 )

Type material. Holotype: female, NSMT-Ar 22039, Sesoko Island , Sesoko , Motobu Town, Kunigami District, Okinawa, Japan (26.643978°N, 127.867065°E), 2 June 2021, K. Okazaki leg. Paratypes: 1 male, NSMT-Ar 22040, Kijyoka , Ōgimi Village, Kunigami District, Okinawa, Japan (26.694485°N, 128.146732°E), 15 April 2021, Y . Suzuki leg .; 1 male, NSMT-Ar 22041, Kume Island , Ōta , Kumejima Town, Shimajiri District, Okinawa, Japan (26.348345°N, 126.755051°E), 18 May 2022, N . Nakama leg .

Other specimens examined. One juv . Kuroishimori Park , Majya , Kumejima Town, Shimajiri District, Okinawa, Japan (26.365306°N, 126.805788°E), 16 May 2022, K . Yoshida leg .; 1 juv . Nishimei , Kumejima Town, Shimajiri District, Okinawa, Japan (26.363140°N, 126.764791°E), 18 May 2022, N . Nakama leg .

Etymology. The specific name refers to the bicolored body of the holotype.

Diagnosis. Cladothela bicolor sp. nov. bears flattened cheliceral fangs and endites, with dense short stiff bristles ( Fig. 1C–I ), a character shared with C. auster and C. oculinotata ( Kamura 1991, 1997). However, female of C. bicolor sp. nov. can be distinguished from both species based on the following unique characteristics: an elliptical, transversely wider copulatory openings surrounded with distinctive sclerotized ridges [vs. ridges located on mesial and anterior sides of copulatory openings in C. auster ; mesial and posterior sides in C. oculinotata ; Figs 2K, L , 3A vs. fig. 3 in Kamura (1997) and figs 30, 31 in Kamura (1991)]; copulatory ducts as wide as and 2.5 times as tall as spermathecae, and curved, and close to each other before inserting to spermathecae [vs. copulatory ducts straight and narrower than spermatheca width in C. auster and 1.5 times as tall as spermathecae and bent before inserting to spermathecae in C. oculinotata ; Figs 2M , 3B (CD) vs. fig. 4 in Kamura (1997) and fig. 32 in Kamura (1991)]; spermathecae close to each other [vs. further apart from each other in C. auster and C. oculinotata ; Figs 2M , 3 vs. fig. 4 in Kamura (1997) and fig. 32 in Kamura (1991)]. Male of C. bicolor sp. nov. can be distinguished from C. auster and C. oculinotata by the following characteristics of male palps: embolus relatively thin (embolus width/length 0.056) [vs. relatively thicker in C. auster : embolus width/length 0.106; and thinner in C. oculinotata : embolus width/length 0.032; Figs 2Q , 3D vs. fig. 1 in Kamura (1997) and fig. 26 in Kamura (1991)], conductor with a dark-colored distinct angular ridge on the retrolateral margin, and base of the conductor having a wide, whitish, non-sclerotized membranous region [vs. conductor having a sclerotized lobe-like structure in C. auster , ridge on retrolateral margin of conductor rounded in C. oculinotata ; Figs 2P–R , 3C–E vs. fig. 1 in Kamura (1997) and fig. 26 in Kamura (1991)]; tegulum very weakly protruded [vs. strongly protruded in C. oculinotata ; Figs 2R , 3E vs. fig. 27 in Kamura (1991)].

Live individuals of C. bicolor sp. nov. possess a clear bicolor body: vivid red prosoma and black abdomen ( Fig. 1A, B ), readily to distinguish the new species from its congeners, which possess uniformly dark reddish brown or dark brown body color.

Description. Female (holotype: NSMT-Ar 22039). Body 5.66 long. Carapace 2.44 long, 2.07 wide, 0.74 high. Eye size and interdistances: AME 0.184, ALE 0.211, PME 0.200, PLE 0.157, AME–AME 0.091, AME–ALE 0.038, PME–PME 0.084, PME–PLE 0.069, ALE–PLE 0.059. Leg length: I: 1.87+0.99+1.41+0.91+0.69=5.87; II: 1.60+ 0.93+1.28+0.85+0.68=5.34; III: 1.39+0.82+1.06+0.92+ 0.70=4.89; IV: 1.79+0.93+1.45+1.62+0.95=6.74. Abdomen 3.06 long, 2.33 wide, 1.71 high.

Chelicerae as long as wide (length/width 1.21) with 3 small promarginal teeth almost in form of small denticles and bearing dense short stiff bristles, retromarginal teeth absent. Fang wide, flat and curved. Epigyne ( Figs 2K, L , 3A ): epigynal plate trapezoidal, wider than long (plate length/ width 0.78); pair of window-like, weakly pigmented regions on anterolateral sides of epigynal plate (arrows in Fig. 2K ); posteromedian part weakly sclerotized with two pigmented, pit-like structures on posterior margin (arrows in Fig. 2L ); interdistace of copulatory openings longer than copulatory opening width: interdistance/width 2.15, elliptical, transversely wider with clear sclerotized ridges surrounding the openings; anterior side of epigynal plate sclerotized and pigmented, posterior side membranous and less pigmented. Internal genitalia ( Figs 2M , 3B ): copulatory ducts massive, elongated, curved, contiguous before inserting to spermathecae; lateral glands attenuating transversely; spermathecae globular, juxtaposed; fertilization ducts arising from mesial sides of spermathecae.

Coloration ( Fig. 1 ). Carapace vividly red in live individuals, and reddish brown in specimens preserved in alcohol. Mouthparts and sternum reddish brown. Legs dark reddish brown with coxae, trochanters, metatarsi and tarsi pale. Dorsum of abdomen black in live individuals, dark grey in preserved specimens, with 2 pairs of sigilla; venter of abdomen pale whitish brown.

Male (paratype: NSMT-Ar 22040). Body 5.58 long. Carapace 2.55 long, 2.11 wide, 0.76 high. Eye size and interdistances: AME 0.153, ALE 0.181, PME 0.185, PLE 0.164, AME–AME 0.098, AME–ALE 0.024, PME–PME 0.062, PME–PLE 0.060, ALE–PLE 0.057. Length of legs: I: 1.96+ 0.85+1.51+0.88+0.86=6.06; II: 1.63+0.73+1.27+0.78+ 0.82=5.23; III: 1.30+0.69+0.91+0.90+0.66=4.46; IV: 2.26+0.85+1.51+1.67+0.83=7.12. Abdomen 2.91 long, 1.79 wide, 1.33 high.

Carapace, mouthparts, and legs as in females. Chelicerae as long as wide (length/width 1.28) with 3 promarginal teeth, retromarginal teeth absent. Palp ( Figs 2N–R , 3C–E ): femur slightly longer than cymbium (femur length/cymbial length 1.40); base of femoral spine positioned slightly upper than half of femur (distance between basal margin of palpal femur and base of femoral spine/femoral length 0.60); patella longer than tibia (patella length/tibia length 1.50); cymbium longer than wide (length/width 1.68); base of conductor with a wide, whitish, non-sclerotized membranous region; conductor with hooked tip, dark-colored, distinct angular ridge on retrolateral margin (triangular outgrowth); embolus moderately long, weakly twisted, emerging from prolateral base of tegulum. Abdomen with 2 pairs of sigilla and a trapezoid scutum on anterior part of dorsum.

Coloration. As in female.

Habitat. Specimens were collected from litter layers and under stones in primary and secondary broad-leaf forests.

Distribution. Okinawa Islands (Sesoko, Okinawa and Kume Islands), Japan.

Note. Males and females are regarded conspecific because of the similarity in body color and morphology of cheliceral fangs and endites.

Figures

Fig. 1. Cladothela bicolor Suzuki, sp. nov., holotype female from Sesoko Island (NSMT-Ar 22039: A, C, D) and paratype male from Okinawa Island (NSMT-Ar 22040: B, E, F). A, B, Habitus of living individuals; C, E, habitus, dorsal view; D, F, ditto, ventral view. Scale bars: 1.0mm.

Fig. 2. Cladothela bicolor Suzuki, sp. nov., holotype female from Sesoko Island (NSMT-Ar 22039: A, C, E–G, K–M) and paratype male from Okinawa Island (NSMT-Ar 22040: B, D, H–J, N–R). A, B, Eye region, dorsal view; C, D, mouthparts, ventral view; E, H, left chelicerae, posterior view; F, I, ditto, anterior view; G, J, ditto, ventral view; K, epigyne, ventral view; L, ditto, clarified view; M, internal genitalia, dorsal view; N, right palp, dorsal view; O, ditto, retrolateral view; P, left palp, retrolateral view; Q, ditto, ventral view; R, ditto, prolateral view. Arrows in K and L indicate pit-like structures on posterior margin and window-like regions on epigynal plate, respectively. Scale bars: 1.0mm (O); 0.5mm (A–D, N); 0.2mm (E–M, P–R).

Fig. 3. Genitalia of Cladothela bicolor Suzuki, sp. nov., holotype female from Sesoko Island (NSMT-Ar 22039: A, B) and paratype male from Okinawa Island (NSMT-Ar 22040: C–E). A, Epigyne, ventral view; B, internal genitalia, dorsal view; C, left palp, prolateral view; D, ditto, ventral view; E, ditto, retrolateral view. Abbreviations: CD, copulatory ducts; CDH, copulatory duct height; CDW, copulatory duct width; CO, copulatory opening; Co, conductor; COI, copulatory openings interdistance; COW, copulatosy opening width; Em, embolus; EmL, embolus length; EmW embolus width; FD, fertilization duct; G, lateral gland; Sp, spermatheca; SpH, spermatheca height; spermatheca width; T, tegulum; To, triangular outgrowth. Arrow indicates a hook-like apophysis on retrolateral side of palpal femur. Scale bars:0.2mm.