Cybaeus sanbruno Bennett 2009

Bennett, Robb, Copley, Claudia & Copley, Darren, 2019, Cybaeus (Araneae: Cybaeidae): the adenes species group of the Californian clade, Zootaxa 4711 (2), pp. 245-274 : 262-263

Cybaeus sanbruno Bennett 2009

Figs 44–49 , 67–68 , 70

Cybaeus sanbruno Bennett in Copley et al. 2009: 383 , Figs 54–60 . World Spider Catalog 2019. Type material. Holotype ♂. U.S.A.: California: San Mateo County, San Bruno Mountain, Crystal Cave Canyon, 14 December 1980, D. Ubick (CAS), examined.

Other material examined. Specimens and locality data in Copley et al. (2009).

Diagnosis. The male of C. sanbruno is diagnosed by a combination of features of the patellar apophysis and the proximal arm of the tegular apophysis. The patellar apophysis has 13 peg setae in an antero-dorsal cluster ( Fig. 45 ). The tip of the proximal arm of the tegular apophysis is bifid with the terminations pincer-like and convergent and there is a small but prominent, pointed dorsal keel ( Figs 44 , 67–68 ). The males of the two other adenes group species with a bifid tip of the proximal arm of the tegular apophysis either have the terminations divergent and an inconspicuous dorsal keel and, on the patellar apophysis, a larger number of peg setae ( C. adenes : Figs 1–2 , 59–60 ) or have the terminations of the proximal arm of the tegular apophysis only weakly convergent and not pincer-like and the peg setae arranged more-or-less linearly along the tip and dorsal edge of the patellar apophysis ( C. schusteri : Figs 51 , 65 )

The female is distinguished by its inverted U-shaped atrium, widest posteriorly and with the posterior ends curved anteriorly (the latter feature is inconspicuous but visible in cleared epigynum using a compound microscope) ( Figs 47–48 ). In addition the very short, thick-walled, contiguous (or nearly so) copulatory ducts ( Figs 48–49 ) are diagnostic. None of the other adenes group females have atria or copulatory ducts of this form.

Description. See Copley et al. (2009). Palpal tibia with small retrolateral ridge anteriorly, dorsal to the carinate retrolateral tibial apophysis ( Fig. 46 ).

Distribution and natural history. Known only from San Bruno Mountain, San Mateo County, in west central California ( Fig. 70 ). See Copley et al. (2009).

Figures

FIGURE 70. Distributions of Cybaeus auburn spec. nov. (▪), C. reducens (□), C. sanbruno (), C. schusteri spec. nov. (●). CA—California, OR—Oregon, NV— Nevada.

FIGURES 44–46. Cybaeus sanbruno, male from San Bruno Mountain, California, left palpus (44 genital bulb, ventral; 45 patella and tibia, dorsal; 46 patella and tibia, retrolateral). DK—dorsal keel of proximal arm of tegular apophysis, RR—retrolateral ridge dorsal to retrolateral tibial apophysis. Scale bars: 0.1 mm.

FIGURES 47–49. Cybaeus sanbruno, females from San Bruno Mountain, California, copulatory organ (47 epigynum, ventral; 48 vulva, ventral; 49 same, dorsal). Scale bars: 0.1 mm.

FIGURES 65–68. Cybaeus spp., male left palpi, detail of tegular apophysis. 65–66 C. schusteri spec. nov. holotype. 67–68 C. sanbruno from San Bruno Mountain, California (65 proximal arm, ventral; 66 tegular apophysis, retrolateral; 67 proximal arm, ventral; 68 tegular apophysis, retrolateral). Red lines indicate convergence of tips of proximal arm. DK—dorsal keel of proximal arm of tegular apophysis, E—embolus. Scale bars: 0.05 mm (Figs 65, 67), 0.1 mm (Figs 66, 68).

FIGURES 54–55. Cybaeus torosus spec. nov., female holotype, copulatory organ (54 epigynum, ventral; 55 vulva, dorsal). Scale bars: 0.1 mm.

FIGURES 56–60. Cybaeus spp., male left palpi, detail of tegular apophysis. 56 C. amicus from San Mateo County, California. 57–58 C. reducens from Santa Clara County, California. 59 C. adenes from San Francisco, California. 60 C. adenes from San Geronimo, California (56–57 proximal arm, ventral; 58 tegular apophysis, retrolateral; 59–60 proximal arm, ventral). Red arrows indicate single (Fig. 56) and trifid (Fig. 57) tips of proximal arm. Red lines indicate divergence of tips of proximal arm. DA—distal arm of tegular apophysis, DK—dorsal keel of proximal arm of tegular apophysis, E—embolus, PA—proximal arm of tegular apophysis. Scale bars: 0.05 mm (Figs 56–57, 59–60), 0.1 mm (Fig. 58).

FIGURES 1–3. Cybaeus adenes, male from San Francisco, California, left palpus (1 genital bulb, ventral; 2 patella and tibia, dorsal; 3 patella and tibia, retrolateral). DA—distal arm of tegular apophysis, E—embolus, PA—proximal arm of tegular apophysis, PTA—patellar apophysis, RR—retrolateral ridge dorsal to retrolateral tibial apophysis, RTA—retrolateral tibial apophysis. Scale bars: 0.1 mm.

FIGURES 50–53. Cybaeus schusteri spec. nov. (50–52 male holotype, left palpus; 53 female from south of Monticello, California), copulatory organ (50 genital bulb, ventral; 51 patella and tibia, dorsal; 52 patella and tibia, retrolateral; 53 vulva, ventral). DK—dorsal keel of proximal arm of tegular apophysis, RR—retrolateral ridge dorsal to retrolateral tibial apophysis. Scale bars: 0.1 mm.