Utivarachna tamdao Chu & Li, 2023

Chu, Chang, Li, Shuqiang, Pham, Dinh-Sac & Yao, Zhiyuan, 2023, Three new species of the spider genus Utivarachna Kishida, 1940 (Araneae, Trachelidae) from China and Vietnam, ZooKeys 1181, pp. 201-217 : 201

publication ID	https://dx.doi.org/10.3897/zookeys.1181.110628
publication LSID	lsid:zoobank.org:pub:AB0B755A-C530-46CD-87F2-77599B974343
persistent identifier	https://treatment.plazi.org/id/7CC2C53C-5BBB-49BD-A81E-13835F82B7E5
taxon LSID	lsid:zoobank.org:act:7CC2C53C-5BBB-49BD-A81E-13835F82B7E5
treatment provided by	ZooKeys by Pensoft
scientific name	Utivarachna tamdao Chu & Li
status	sp. nov.

Treatment

Utivarachna tamdao Chu & Li View in CoL sp. nov.

Figs 4 View Figure 4 , 5 View Figure 5 , 6 View Figure 6

Type materials.

Holotype ♂ (IZCAS-Ar44630): Vietnam: Vinh Phuc Province: Tam Dao National Park, natural forest (21.4872°N, 105.6201°E, 870 m a.s.l.), hand caught in leaf litter, 18.IX.2007, leg. Dinh-Sac Pham. Paratypes: 1♂ (IZCAS-Ar44631) and 2♀ (IZCAS-Ar44632, 44633), same data as holotype.

Etymology.

The specific name is named after type locality; noun in apposition.

Diagnosis.

The new species resembles U. kinabaluensis Deeleman-Reinhold, 2001 (cf. Figs 4 View Figure 4 - 6 View Figure 6 and Deeleman-Reinhold 2001: 381, figs 593-597), as males have a similar U-shaped sperm duct (SD) (Fig. 4B View Figure 4 ), the tegulum is widest in anterior part (Fig. 4B View Figure 4 ), the embolus (E) is coiled (Fig. 4A-C View Figure 4 ), females have a nearly trapezoidal atrium (A) (Fig. 5A View Figure 5 ), connecting ducts (CnD) are thin and slender (Fig. 5B View Figure 5 ), and fertilization ducts (FD) are laminar (Fig. 5B View Figure 5 ). Males can be distinguished in having the RTA widest at its base (Fig. 4B, C View Figure 4 ; vs RTA widest at middle, distally with hook-shaped apophysal claw in U. kinabaluensis ). Females can be distinguished from U. kinabaluensis in having the copulatory openings (CO) located anteriorly (Fig. 5A View Figure 5 ; vs posteriorly), the atrium large, occupying about 2/3 of the epigyne length (vs atrium small, occupying about 1/4 of the epigyne length), the copulatory ducts (CD) forming irregular loops and these loops located anteriorly (Fig. 5B View Figure 5 ; vs copulatory ducts regularly coiled and these coils medially located), the bursae (B) located between the copulatory ducts and spermathecae (SP), anterior part strongly constricted and curved, and posterior part three times width of anterior part (Fig. 5B View Figure 5 ; vs bursae located in anterior of copulatory ducts, base to middle part strongly constricted and curved, posterior part five times the width of the anterior part), and the spermathecae globular (Fig. 5B View Figure 5 ; vs gourd-shaped). The new species also resembles U. lata Jin, Yin & Zhang, 2015 (cf. Figs 4 View Figure 4 - 6 View Figure 6 and Jin et al. 2015: 570, figs 1-3) as males have a similar U-shaped sperm duct (Fig. 4B View Figure 4 ), leaf-shaped subtegulum (ST) in ventral view (Fig. 4B View Figure 4 ), and long RTA (Fig. 4B, C View Figure 4 ), and females have similar copulatory openings located anteriorly (Fig. 5A View Figure 5 ), a large atrium (Fig. 5A View Figure 5 ), and globular spermathecae (Fig. 5B View Figure 5 ). Males can be distinguished by the oval bulb, which is widest in anteriorly (Fig. 4B View Figure 4 ; vs almost square in U. lata ) and by the curved basal portion of the embolus (Fig. 4B, C View Figure 4 ; vs oblique in U. lata ). Females can by distinguished by the copulatory openings width/atrium posterior width: 1/6 (Fig. 5A View Figure 5 ; vs copulatory openings width/atrium posterior width: 1/2 in U. lata ), by the copulatory ducts forming irregular loops (Fig. 5B View Figure 5 ; vs copulatory ducts coiled three times around the anterior of connecting duct in U. lata ), and by the bursae anterior part strongly constricted and curved (Fig. 5B View Figure 5 ; vs bursae anterior part slightly constricted and curved, posterior end very close to spermathecae in U. lata ).

Description.

Male. Habitus (Fig. 6A, B View Figure 6 ). Total length 4.68. Carapace (Fig. 6A View Figure 6 ): length 2.48, width 1.86, deep reddish brown; cervical groove, radial grooves, and fovea indistinct. Eyes (Fig. 6A View Figure 6 ): AER procurved, PER recurved in dorsal view, PER wider than AER. Eye sizes and interdistances: AME 0.15, ALE 0.13, PME 0.13, PLE 0.14; AME-AME 0.06, AME-ALE 0.12, PME-PME 0.19, PME-PLE 0.27; MOA 0.36 long, anterior width 0.34, posterior width 0.46. Mouthparts (Fig. 6B View Figure 6 ): chelicerae deep reddish brown, with three promarginal (middle largest) and five retromarginal (proximal largest, distal smallest) teeth; endites depressed posteriorly, slightly convergent anteriorly, with dense setae on inner margin; labium nearly trapezoidal, length 0.47, width 0.39. Sternum (Fig. 6B View Figure 6 ) length 1.29, width 0.97, deep reddish-brown, with dark edges, with precoxal triangles and intercoxal extensions, posterior region protruding strongly between coxae IV. Pedicel cylindrical, sclerotized, relatively short, reddish brown. Abdomen (Fig. 6A, B View Figure 6 ) grey, 2.20 long, 1.75 wide, dorsum with scutum covering more than half of dorsal surface, with four brown central spots; venter with indistinct two lines of spots in the median field. Spinnerets yellow. Legs: anterior legs reddish brown, distinctly thicker than yellowish-brown posterior legs. Leg measurements: I 6.03 (1.83, 0.77, 1.55, 1.18, 0.70); II 4.82 (1.62, 0.71, 0.89, 1.07, 0.53); III 4.37 (1.26, 0.62, 0.89, 1.07, 0.53); IV 5.50 (1.52, 0.67, 1.20, 1.52, 0.59).

Palp (Fig. 4A-C View Figure 4 ): tibia shorter than half of cymbium length; RTA about 0.98 times longer than tibia, distinctly narrow subdistally to distally, with distinct anterior curvature distally. Bulb oval, widest in anterior part; tegulum approximately 1.39 times as long as its maximum width in ventral view; subtegulum (ST) sclerotized, occupying approximately 1/3 of tegulum width in ventral view; sperm duct (SD) distinct, U-shaped in ventral view, extending to base of tegulum. Embolus (E) long, anticlockwise, obliquely coiled twice, coils as wide as maximum width of tegulum; basal portion of embolus lamellar, wide, arising at 2:30 o’clock from bulb; terminal portion of embolus filiform, resting in distal cymbial alveolus.

Female. Habitus (Fig. 6C, D View Figure 6 ). As in male except as noted. Total length 5.34. Carapace length 2.70, width 2.02, reddish brown; fovea distinct, dark, and short. Eye (Fig. 6C View Figure 6 ) sizes and interdistances: AME 0.12, ALE 0.13, PME 0.13, PLE 0.13; AME-AME 0.09, AME-ALE 0.12, PME-PME 0.21, PME-PLE 0.25; MOA 0.32 long, anterior width 0.31, posterior width 0.44. Mouthparts (Fig. 6D View Figure 6 ): chelicerae with three promarginal (middle largest) and five retromarginal (proximal largest, distal smallest) teeth. Sternum (Fig. 6D View Figure 6 ) length 1.50, width 1.17, reddish brown. Abdomen (Fig. 6C, D View Figure 6 ): length 2.54, width 2.08, dorsum with four central, indistinct, reddish-brown spots; venter without pattern. Spinnerets surrounded by brown rings. Leg measurements: I 5.56 (1.64, 0.75, 1.32, 1.12, 0.73); II 5.24(1.54, 0.69, 1.19, 1.14, 0.68); III 4.41 (1.24, 0.63, 0.90, 1.07, 0.57); IV 5.73 (1.57, 0.66, 1.27, 1.58, 0.65).

Epigyne (Fig. 5A, B View Figure 5 ): epigynal plate longer than wide, spermathecae distinct and bursae indistinct in ventral view. Atrium (A) large and nearly trapezoidal, occupying about 2/3 of epigyne length, posterior margin wider than anterior margin. Copulatory openings (CO) semicircular, located at anteriorly, separated by about their diameter. Copulatory ducts (CD) long, anterior part wide and posterior part narrow; copulatory ducts convoluted posteriorly, forming irregular loops. Connecting ducts (CnD) thin and slender, located on lateral areas of copulatory openings, separated by more than spermathecae (SP) diameter. Bursae (B) nearly rod-shaped, anterior part strongly constricted and curved, posterior part three times width of anterior part; bursae with several small clusters of glandular particles (GP) on surface of distal margin. Spermathecae globular, separated by less than half of their diameter. Fertilization ducts (FD) laminar, separated from each other by posterior width of atrium.

Distribution.

Vietnam (Vinh Phuc, type locality; Fig. 10 View Figure 10 ).