Bioacoustics of Agyneta yukona

Description: Male : Total length 1.77; carapace length 0.80, width 0.58. CEPHALOTHORAX: Carapace light brown, shiny, finely reticulate; suffused with dark gray along margin, radiating lines. Sternum brown strongly suffused with dark gray. Clypeus height 2. Chelicerae orange-brown apical part lighter, excavated; ~ 12 seta-tipped tubercles; promargin two denticles, retromargin four denticles; without projections near base of fang. Cheliceral stridulatory organ ~39 striae, well spaced, getting slowly closer together basally. ABDOMEN: Uniformly gray. LEGS: Yellow; leg I total length: 2.62; leg III total length: 1.89; Tm I: 0.28, Tm IV: absent. GENITALIA: Palpal retrolateral tibial apophysis small, slightly rugose; dorsal tibial apophysis rounded and rugose; two retrolateral trichobothria and a dorsal one ( Fig.144 ). Cymbium triangular; glabrous depression present ( Fig. 144 ); dorsal cymbial tubercle rounded and smooth; ventral cymbial tubercle pointed and smooth; prolateral notch shallow ( Fig. 145 ). Paracymbium apical pocket short, anterior pocket curved and long forming a large cover, posterior pocket short and curved ( Fig. 144 ). Embolus tip pointed, straight; apically with bifid prong; basally with bifid flange and few small spines; Fickert’s gland absent; ventral lamella wide and rugose, broken in the middle; thumb reaching below the embolus proper ( Fig. 146 ). Embolus proper set apically, dorsal part narrower ( Fig. 146 ). Anterior terminal apophysis wide with short protrusions; posterior terminal apophysis wide, striated; lamella characteristica large, three spurs basally, ending in a sharp point ( Fig. 147 ). Female : Total length 1.97; carapace length 0.67, width 0.55. CEPHALOTHORAX: Same coloration as male. Chelicerae yellow; promargin four teeth, retromargin three denticles. Cheliceral stridulatory organ ~22 striae, well spaced. ABDOMEN: Same as male. LEGS: Same as male; palpal tibia and tarsus brownish, tarsal claw absent; leg I total length: 2.63; leg III total length: 1.99; Tm I: 0.27, Tm IV: absent. GENITALIA: Epigynum with proximal part of scape wide, basally straight, narrowing apically; epigynal slits very large and oval; pit hook depression shallow ( Fig. 148 ); lateral lobes long and wide; stertcher and pit small ( Fig. 149 ). Median part of scape long and wide; genital pores situated at base of lateral lobes pockets ( Fig. 150 ). Internal genitalia with elongated, obliquely oriented receptacula ventrally and a small rounded dorsal one ( Figs 149, 150 ).