Yamaneta Miller & Lin

Feng, Chengcheng, Miller, Jeremy A., Lin, Yucheng & Shu, Yunfei, 2019, Further study of two Chinese cave spiders (Araneae, Mysmenidae), with description of a new genus, ZooKeys 870, pp. 77-100 : 83-85

Genus Yamaneta Miller & Lin gen. nov.

Type species.

Maymena paquini Miller, Griswold & Yin, 2009.

Etymology.

Formed from Yama, the figure in Chinese mythology who oversees the realm of the dead, and - neta (-νήτης), an element in several spider names conventionally taken to mean ‘spinner’ ( Cameron 2005). The gender is masculine.

Diagnosis.

Distinguished from other mysmenid genera except Maymena by the presence of a modified spatulate seta on the PLS ( Miller et al. 2009: fig. 57 D, F; Lopardo and Hormiga 2015: fig. 11 G, H), the proximal position of the male metatarsus I clasping spur (more proximal in Maymena than Yamaneta ; Miller et al. 2009: fig. 53 A; Lopardo and Hormiga 2015: fig. 16 G), the shape of the apical part of the cymbium, which appears to form a functional conductor ( Miller et al. 2009: fig. 55 A; Lopardo and Hormiga 2015: fig. 10 D, G) that interacts with the embolus. The presence of trichobothria on the male palpal tibia is a rare character in Mysmenidae , occurring in such genera as Maymena , Yamaneta , Trogloneta , Mysmenopsis Simon 1898 and Isela Griswold, 1985. Distinguished from Maymena by the elongate male palpal tibia and patella, long and setose epigynal scape, by the absence of a modified seta with a long row of branches near the major ampullate gland spigot on the anterior lateral spinnerets ( Miller et al. 2009: fig. 57 B), and by the clustered arrangement of male epiandrous fusules ( Miller et al. 2009: fig. 56 D; dispersed in Maymena : Lopardo and Hormiga 2015: figs 12 B, 16 A). The type species Maymena mayana (Chamberlin & Ivie, 1938) has been described as having a small rounded scape ( Gertsch 1960), although this is a glabrous structure (setose in Yamaneta ), and M. mayana is coded as absent for a scape in phylogenetic data matrices ( Lopardo et al. 2011, Lopardo and Hormiga 2015: character 60). There are also similarities in the female reproductive path shared between M. mayana and Yamaneta , such as the fertilization ducts arising from the copulatory ducts rather than the spermathecae ( Lopardo and Hormiga 2015: fig. 128 B); internal female reproductive structures and spinneret spigot morphology have been documented for only a few Maymena species.

Description.

Relatively large mysmenids (> 2 mm). Femoral spots on legs I and II in female, leg I only in male. Legs with macrosetae on the femora, tibiae, and metatarsi, especially in the anterior legs. Male clasping spurs arise from distal part of tibia I and basal third of metatarsus I. Leg formula IV-I-II-III. Carapace subovate, ocular area slightly raised. Eight eyes in two rows. AME black and with dark base, others reflective. ALE and PLE contiguous. ARE procurved, PRE straight ( Fig. 4 ). Clypeus moderately high, inclined from anterior lip to eye region. Cervical groove and thoracic fovea indistinct. Thoracic region flat, smooth, nearly hairless except for the eye region and midline. Chelicerae strong, deeper color than carapace. Endites nearly rectangular. Labium rectangular, fused to sternum. Sternum heart-shaped, flat, hirsute, posterior corner sharp ( Figs 4 B, E , 7 B, E ). Abdomen globular dorsally, ovate laterally, mottled light to medium gray or tan, sparsely covered with black setae. Spinnerets distinctly sclerotized, the anteriors larger than the posteriors; colulus small, with two tiny setae; anal tubercle pale yellow ( Figs 4 , 7 ). Male palpal patella and tibia elongate, palpal tibia with at least one trichobothrium. Hook-like apophysis on prolateral face of cymbium ( Miller et al. 2009: fig. 55 C). Cymbium folded distally, forming functional conductor. Tegular conductor absent. Embolus long and filiform arising from proximal part of palpal bulb. Epigyne with setose scape extending nearly to the tracheal spiracle ( Figs 4 E, F , 7 E, F ). Scape with notched lateral margins ( Figs 6 D , 9 D ), profile distinctly curved at dorsum ( Figs 6 B , 9 B ). Spermathecae globular, copulatory ducts arise from mesal part of spermathecae, loop near base of scape, terminate in paired openings near middle of scape ( Figs 6 C, D , 9 C, D ). Fertilization ducts arise from copulatory ducts rather than spermathecae ( Figs 6 D , 9 D ). Male epiandrous fusules with clustered arrangement ( Miller et al. 2009: fig. 56 D). PLS with modified spatulate seta ( Miller et al. 2009: fig. 57 D, F; Lopardo and Hormiga 2015: fig. 11 G, H).

Composition.

Yamaneta kehen (Miller, Griswold & Yin, 2009) comb. nov., Yamaneta paquini (Miller, Griswold & Yin, 2009) comb. nov.

Distribution.

Gaoligong Mountains, Yunnan, China.

Affinity with Maymena .

Lopardo and Hormiga (2015) highlighted several key morphological characteristics of Maymena and discussed their status as putative synapomorphies and utility as diagnostic characters. These observations were based on a selection of western species, but many of the characteristics discussed are consistent with Yamaneta . The modified spatulate seta on the PLS ( Lopardo and Hormiga 2015: fig. 11 G, H) is present in Yamaneta paquini ( Miller et al. 2009: fig. 57 D, F [indicated by arrow]). The variable shape of the aciniform gland spigots on both pairs of posterior spinnerets and in both sexes ( Lopardo and Hormiga 2015: fig. 11F-H, 13 F, G) is visible in Yamaneta paquini ( Miller et al. 2009: fig. 57 C–F). However, the modified seta with a long row of branches near the major ampullate gland spigot on the anterior lateral spinnerets ( Lopardo and Hormiga 2015: fig. 11 E, 13 C, 16 B) is not visible in Yamaneta paquini ( Miller et al. 2009: fig. 57 B). The presence of macrosetae on the femora, tibiae, and metatarsi, especially on the anterior legs ( Lopardo and Hormiga 2015: figs 140 M, 141 C), is shared by Maymena , Yamaneta ( Miller et al. 2009: fig. 53 A, B, see also text), and the kleptoparasitic clade Mysmenopsinae. A roughly cylindrical palpal tibia (i.e., distal width less than two times proximal width; Lopardo and Hormiga 2015: fig. 10 A) is difficult to discern in Yamaneta , which have the palpal tibia elongated and modified in shape compared to Maymena species ( Figs 5 , 8 ). Like Maymena , males of Y. paquini and Y. kehen have a femoral spot on femur I, a clasping spur in a proximal position on male metatarsus I ( Miller et al. 2009: fig. 53 A; Lopardo and Hormiga 2015: fig. 16 G), and lack a tegular conductor. Also consistent across Maymena and Yamaneta is the presence of macrosetae on the female palpal tarsus ( Miller et al. 2009: fig. 53 B; Lopardo and Hormiga 2015: figs 13 A, 15 A). Unlike the Maymena species studied by Lopardo and Hormiga (2015: fig. 10 H), Yamaneta species do not appear to have a deeply grooved embolic rim. As in the Maymena species studied by Lopardo and Hormiga (2015), described as having the primary cymbial conductor apically bent over the ventral side ( Lopardo and Hormiga 2015: figs 10 D, G, 14 D), the cymbium of Yamaneta species has a complex, almost helical shape, with the embolus and cymbium interacting distally ( Figs 5 , 8 ; Miller et al. 2009: figs 54, 55 A, B). Unlike Maymena ( Lopardo and Hormiga 2015: figs 12 B, 16 A), where the epiandrous fusules are arranged in a dispersed row, those of Y. paquini are arranged in a few rough clusters ( Miller et al. 2009: fig. 56 D). Lopardo and Hormiga (2015: 778) report that the respiratory system of Maymena distinguishes it from other mysmenids, but this has not been investigated for Yamaneta .

Figures

Figure 4. Yamaneta kehen (Miller, Griswold & Yin, 2009) comb. nov. from Fugong Co., Lishadi, " a nameless cave " A-C Male habitus D-F female habitus A, D dorsal B, E ventral C, F lateral. Scale bars: 0.50 mm.

Figure 5. Yamaneta kehen (Miller, Griswold & Yin, 2009) comb. nov. from Fugong Co., Lishadi, " a nameless cave ", male A, B, E, F Left palp C cymbium D palpal bulb G partial leg I A, E, G prolateral B, F retrolateral C prolateral D retrolateral. Abbreviations: BC base of cymbium; BH basal haematodocha; CA cymbial apophysis; CS clasping spine on leg I; Cy cymbium; CyC cymbial conductor; CyFs setae on cymbial fold; E embolus; PC paracymbium; SD spermatic duct; T tegulum; Ti tibia; TS tibial spine on leg I; TTr trichobothrium on tibia; TiS setae on palpal tibia. Scale bars: 0.50 mm.

Figure 6. Yamaneta kehen (Miller, Griswold & Yin, 2009) comb. nov. from Fugong Co., Lishadi, " a nameless cave ", female genitalia A, B Epigyne C-D vulva (lactic acid treated) A, C ventral B lateral D dorsal. Unlabeled arrow in B indicates curved profile of dorsal surface of scape, in D indicates notched lateral margin of scape. Abbreviations: CD copulatory ducts; FD fertilization ducts; S spermathecae; Sp scape. Scale bars: 0.10 mm.

Figure 7. Yamaneta paquini (Miller, Griswold & Yin, 2009) comb. nov. from Lushui Co., Daxingdi, Walayaku [cave], male and female A-C Male habitus D-F female habitus A, D dorsal B, E ventral C, F lateral. Scale bars: 0.50 mm.

Figure 8. Yamaneta paquini (Miller, Griswold & Yin, 2009) comb. nov. from Lushui Co., Daxingdi, Walayaku [cave], male A, B, E, F Left palp C cymbium D palpal bulb G partial leg I A, E, G prolateral; B, F retrolateral; C prolateral; D retrolateral. Abbreviations: BC base of cymbium; BH basal haematodocha; CA cymbial apophysis; CS clasping spine on leh I; Cy cymbium; CyC cymbial conductor; CyFs setae on cymbial fold; E embolus; PC paracymbium; SD spermatic duct; T tegulum; Ti tibia; TS tibial spine on leg I; TTr trichobothria on tibia; TiS seta on palpal tibia. Scale bars: 0.50 mm.

Figure 9. Yamaneta paquini (Miller, Griswold & Yin, 2009) comb. nov. from Lushui Co., Daxingdi, Walayaku [cave], female genitalia A, B Epigyne C-D vulva (lactic acid treated) A, C ventral B lateral D dorsal. Unlabeled arrow in B indicates curved profile of dorsal surface of scape, in D indicates notched lateral margin of scape. Abbreviations: CD copulatory ducts; FD fertilization ducts; S spermathecae; Sp scape. Scale bars: 0.10 mm.