Bioacoustics of Sisicus volutasilex

Description. Male (n=5) : Total length: 1.22–1.24; carapace length: 0.56–0.57; carapace width: 0.45– 0.51; carapace shiny, rounded ( Fig. 25 ), light yellow (141M), midline lightly suffused with gray (402M) bearing a row of 8 forward-pointing setae extending from dorsal groove to posterior eye row, the first one being the longest, and some scattered setae in the eye region along with a brush of long, curved setae on clypeus ( Fig. 26 ). Sternum light yellow (141M), lightly suffused with gray (402M). Chelicerae light yellow (141M); promargin with 5 teeth, retromargin with 4–5 denticles, cheliceral stridulatory organ visible, with ~ 55 striae; associated stridulatory pick present at base of palpal femur. Abdomen uniformly colored, light gray (cool gray 3M) to dark gray (cool gray 7M), densely covered with long semi-erect setae; book lung cover light yellow finely striated. Legs light yellow (141M), leg formula 1423; tibia I–III with two dorsal macrosetae, tibia IV with one such seta; claw not pectinated; metatarsus I with dorsal trichobothrium, Tm I 0.31–0.36; Tm IV absent. Palpus length: 0.22–0.26. Palpal tibia with one retrolateral trichobothria ( Fig. 22 ); paracymbium (P) spiraled, apical part narrow and thin, middle part bearing one long seta, proximal part large with four setae ( Fig. 22 ); tegulum bearing protegulum (PT) without papillae ( Fig. 22 ); suprategulum vestigial, with large, well sclerotized outgrowth ( Fig. 24 ); embolic division complex, embolic membrane (EM) long, well sclerotized, tapered into a serrated apex ( Fig. 24 ); lamella characteristica (LC) robust, curving apically ( Fig. 24 ); radix (R) large, L-shaped in ventral view ( Fig. 21 ); embolus (E) spine-like, moderate size ( Figs 21, 24 ). Female (n=5) : Total length: 1.21–1.31; carapace length: 0.51–0.54 mm ; carapace width: 0.35–0.36 mm ; carapace colora tion as in male, not rounded, shiny, bearing a row of 8 forward-pointing setae extending from dorsal groove to posterior eye row, some scattered setae in the eye region and one seta on clypeus. Coloration of sternum and chelicerae as in male; chelicerae promargin with 5 teeth, retromargin with 5 denticles, cheliceral stridulatory organ visible, with ~ 41 striae; associated stridulatory pick present at base of palpal femur. Abdomen as in male. Female palpal claw absent. Legs coloration and formula as in male; tibia I–III with two dorsal macrosetae, tibia IV with one such seta; claw not pectinated; metatarsus I with dorsal trichobothrium, Tm I 0.30–0.34; Tm IV absent. Epigynum width: 0.09–0.12. Epigynal ventral plate (VP) with V-shaped slit ( Fig. 27 ); dorsal plate scape (DP) protruding into a broad triangular plate ( Fig. 27 ); atrium (A) conspicuous, enlarging posteriorly ( Figs 27–29 ); copulatory openings (CO) located at ventral plate slit, close together, separated by half their width ( Fig. 28 ); copulatory ducts (CD) wide, folded two time ( Figs 28, 29 ); spermathecae (S) oval ( Figs 28, 29 ); fertilization ducts (FD) short and sinuous ( Fig. 29 ).