Solenysa spiralis, Tian & Tu, 2018

Tian, Jiahui & Tu, Lihong, 2018, A new species of the spider genus Solenysa from China (Araneae, Linyphiidae), Zootaxa 4531 (1), pp. 142-146 : 142-145

Solenysa spiralis new species ( Figs. 1–3 )

Etymology. The species name is a Latin word “ spiralis ”, in reference to the spiral embolus of the new species.

Type material examined. Holotype, ♂. China: Sichuan Province, Baoxing County, Yongfu Village , 30.3°N, 120.8°E, 30.ix.2004, L. Tu leg. Paratypes, 3♀, same data, together with the holotype .

Additional material examined. 3♀, China: Sichuan Province, Tianquan County, Yunshigou Village , 30.1°N, 102.7°E, 11.ix.2004, L. Tu leg.

Diagnosis. The male Solenysa spiralis n. sp. can be distinguished from all other Solenysa species by the spiral embolus and the two large cymbial basal processes ( Fig. 1 ); the female is uniquely diagnosed by having the epigynum attached to the abdomen, rather than hanging by a solenoid ( Fig. 3 ).

Description. Small spiders, both sexes similar in general somatic features, which correspond to those of the genus ( Tu & Hormiga 2011). Male total length 1.45; carapace 0.85 long, 0.51 wide; abdomen 0.58 long, 0.53 wide. Cephalic region of both sexes raised, turret-like, bearing AMEs in front, PMEs on top, ALEs and PLEs on each side. Carapace reddish brown, furnished with numerous round pits; lateral margins smooth, without conspicuous lateral lobes that are present in most Solenysa species; posterior part elongated into a tubular-shaped petiole. Chelicerae with three promarginal and five retromarginal teeth. Leg lengths (male): I 3.06 (0.81 + 0.98 + 0.72 + 0.55); II 2.59 (0.75 + 0.77 + 0.60 + 0.47), III 2.18 (0.60 + 0.60 + 0.47 + 0.51); IV 2.56 (0.72 + 0.77 + 0.60 + 0.47). Tm I 0.25, Tm IV. Abdomen grey. Tracheal system of an intermediate type, with median pair unbranched, but extending into prosoma through petiole.

Male palp ( Fig. 1 ). Tibia twice longer than wide, without tibial apophysis. Cymbium with two large basal processes, forming a large basal excavation; the retrobasal process almost rectangular, the probasal process with a pointed tip, turning retrolaterally. Paracymbium torsion-shaped, without an obvious basal curve. Tegulum triangular in retrolateral view. Distal suprategular apophysis stout. Embolic division ( Fig. 2 ): the four elements, radix, embolus, lamella characteristica and terminal apophysis integrated together. Radix not as a distinct sclerite, but combined with lamella characteristica and terminal apophysis. Embolus long and spiral, getting less sclerotized distally, with a large opening, rather than a typical sclerotized proper as it usually is in other linyphiids. Lamella characteristica ribbon-like, bifid distally with two points. Terminal apophysis spine-like, strongly sclerotized, pointing forward.

Epigynum ( Fig. 3 ). Solenoid absent, epigynum attached to the spider’s abdomen. Epigynal plate ventrally bulged, and folding dorsally from each side, covering over epigynal groove slits on dorsal surface. In the cleared and mounted material, copulatory grooves forming a pair of Z-shaped tracings, while fertilization grooves not clear.

Remarks. The taxonomy of linyphiids at the genus level is largely based on genital characters (e.g., Millidge 1984, 1993, Saaristo & Tanasevitch 1996; Saaristo 2007), while somatic features are usually conservative. The genital characters of Solenysa spiralis n. sp. are very different from those of other Solenysa species, forming a special genital type, not corresponding to any of the four known types within this genus ( Tu & Hormiga 2011). Especially, the female S. spiralis n. sp. lacks the solenoid that is a synapomorphy present in all other known Solenysa species ( Tu & Hormiga 2011; Wang et al. 2015). Even though, the new species shares some somatic characters with other Solenysa species, e.g., the raised cephalic region in both sexes, the prolonged petiole, the round pits on the carapace, and an intermediate type of tracheal system. All these are synapomorphies of the Solenysa clade ( Tu & Hormiga 2011; Wang et al. 2015) that suggest that the new species should be placed in Solenysa . The carapace of S. spiralis n. sp. does not have distinct lateral lobes, which is also the case in S. longqiensis Li & Song, 1992 and S. yangmingshana Tu, 2011 ( Tu & Hormiga 2011) that implies its close relationship with the longqiensis clade. The relationships among the species of Solenysa need to be tested in a future study.

Distribution. China (Sichuan).

Figures

FIGURE 1. Solenysa spiralis n. sp. Male palp. A, retrolateral view; B, prolateral view; C, ventral view, arrow points to the large opening of embolus. E, embolus; LC, lamella characteristica; P, paracymbium; PBP, prolateral basal process; RBP, retrolateral basal process; STT, Solenysa tegular triangle; TA, terminal apophysis. Scale bars: mm].

FIGURE 2. Solenysa spiralis n. sp. Male palpal embolic division, dorsal view, arrow points to the large opening of embolus. E, embolus; LC, lamella characteristica; R, radix; TA, terminal apophysis. Scale bars: mm.

FIGURE 3. Solenysa spiralis n. sp. Epigynum. A, ventral view; B, dorsal view; C, dorsal view, cleared; D, lateral view. CG, copulatory groove; CO, copulatory opening; S, spermatheca. Scale bars: mm.