On the desmitracheate " micronetine " genus Nippononeta Eskov, 1992 (Araneae, Linyphiidae) Author Yan, Ming Author Liang, Xiaokai Author Tu, Lihong text ZooKeys 2015 484 95 109 http://dx.doi.org/10.3897/zookeys.484.8663 journal article http://dx.doi.org/10.3897/zookeys.484.8663 1313-2970-484-95 3EA658E472A34A6F98CF776FE7E7A0AB Taxon classification Animalia Araneae Linyphiidae Nippononeta Eskov, 1992 Composition. The genus includes 24 species; the type species is Nippononeta kurilensis Eskov, 1992. Diagnosis (updated). Nippononeta species are similar to Agyneta in many genital characters and the desmitracheate system, but differ in the presence of a dorsal pattern on the abdomen, which is absent in most Agyneta . Male palps of Nippononeta can be distinguished from Agyneta by the conical elevation on the cymbium absent in the former (Fig. 1A), present in the latter; the presence of proximal cymbial fold (Fig. 1D) and the spine-like embolus thumb (Fig. 1G) in Nippononeta , absent in Agyneta . The scaped epigynum in Nippononeta can be distinguished by its narrowed epigynal basal part covered by a transversal fold, the well developed stretcher and remnant lateral lobes (Fig. 2 A-B ), while in Agyneta the epigynal basal part is normal, the stretcher usually small or absent, but the lateral lobes are well developed bearing lateral pockets and copulatory openings ( Tu and Hormiga 2010 : fig. 6a). Figure 1. Nippononeta kurilensis . A-G male palp A retrolateral B ventral C anteroventral D detail of A, arrows indicate the serrated surface of DTA (upper), median branch of paracymbium (left) and outer margin fold continue with distal arm (lower) E-G embolic division E dorsal F ventral, arrow indicates basal hook of embolus G embolus, ventral, upper arrow indicates the last strongest spine of thumb; lower arrow indicates basal hook of embolus H anterior part of male abdomen, ventral, shows epiandrous gland spigots absent. ARP anterior radical process; AX apex of embolus; CRL cymbial retrolateral lobe; DTA distal tibial apophysis; E embolus; EC embolus column; EM embolic membrane; EP embolus proper; LC lamella characteristica; P paracymbium; PF proximal cymbial fold; PH pit hook; PHS pit hook sclerite; R radix; RTP retrolateral tibial process; T tegulum; TA terminal apophysis; TH thumb of embolus. Figure 2. Nippononeta kurilensis . A-D epigynum. A ventral B dorsal C caudal D anterior E tracheal system, with soft tissue digested F female palp G female spinneret spigots, arrow indicates MPA nubbin on ALS H male PLS spigots. AC aciniform gland spigots; AG aggregate gland spigots; ALS anterior lateral spinneret; CG copulatory groove; CY cylindrical gland spigots; FL flagelliform gland spigot; MAP major ampullate gland spigot; mAP minor ampullate gland spigot; PI piriform gland spigots; PLS posterior lateral spinneret; PMS posterior median spinneret; SC scape; ST stretcher; TP turning point; VP ventral plate. Description (updated). Chelicerae of normal size, with narrowed fang base and stronger stridulatory ridges in the male than in the female (Fig. 3 C-F ). Female palpal claw absent (Fig. 2F). Tracheal system: Median trunks wider in diameter than lateral pair, highly branched and extending into prosoma (Fig. 2E); tracheoles with taenidia. Lateral pair and median trunks arising independently from spiracular atrium. Epiandrous gland spigots absent in the male (Fig. 1H). Spinnerets: PLS in females having the mesal cylindrical gland spigot base enlarged (Fig. 2G), the triplet formed by one flagelliform and two aggregate gland spigots present in males PLS (Fig. 2H). For other somatic characters and measurements see Eskov (1992) . Figure 3. Nippononeta kurilensis . A-B female prosoma. A frontal B lateral ( C-F ) chelicera C male, frontal, arrow indicates narrowed fang base D female, frontal E male, ectal F female, ectal. Male palp (Fig. 1 A-G ). Tibia short, with serrated distal apophysis and pointed retrolateral process, sometimes with additional proximal process. Cymbium with small retrolateral lobe and proximal fold above paracymbial base. Paracymbium U-shaped, with median branch arising from inner margin. Distal suprategular apophysis modified into pit hook and hook sclerite. Embolic membrane large, with many papillae. Embolic division: radix boat shaped, connected to embolus by S-shaped membranous column. Embolus with pointed proper and serrated area, thumb modified into many spine-like projections, large apex and basal apophysis. Lamella characteristica usually splitting into two or three branches, at least one of them ribbon like with thread projections distally. Terminal apophysis composed by one large basal sclerite and one or two branches with papillae apex. Epigynum (Figs 2 A-D , 5). Epigynal basal part narrowed, covered by transversal fold formed by the tegument connecting to dorsal side of epigynum. Median plate absent and epigynal cavity dorsally opened. Scape sigmoid folded with well developed stretcher furnished with a pit; lateral lobes remnant; copulatory openings covered by folded scape. Distribution. China, Japan, Korea, Russia.