Atomosphyrus tristiculus Simon, 1902

Barry J. Richardson, 2010, A Review of the Jumping Spider Fauna (Araneae: Salticidae) of Chile, Zootaxa 2418, pp. 1-49 : 14

Atomosphyrus tristiculus Simon, 1902

( Figs 18–25 )

Atomosphyrus tristiculus Simon, 1902: 405 ; 1903: 861, 862; Galiano, 1963: 305 –306, pl. 10, figs 5–8; 1966: 282–284, figs 9–16, 19, 20.

Material examined. CHILE: 13, 1♀ Valle del Rio Mapocho, Santiago , January 1959, H. Zapfe ( BJR854 , MACN5883 ) ; 1♀, Termas de Chillan Road, Puente el Aserradero , 71.45°W, 36.92°S, 30 November 2001, F.G. Andrews ( BJR970 , CAS) .

Diagnosis. The only other species in the genus ( A. breyeri Galiano, 1966 , from Argentina) can be distinguished by the presence of a large tooth in the middle of the anterior face of the chelicera in male A. tristiculus ( Fig. 25 ) and by the shape of the more dorsal of the two apophyses. This has a hook shaped end rather than the square end found in A. breyeri ( Galiano 1966) . In the females, the spermathecae are more than twice the length of a fossa and anterior to the fossae ( Figs 20–21 , unlike A. breyeri .

Description: Male: Body form somewhat ant-like ( Fig. 19 ). Cephalothorax black with a lighter orange area on the pars cephalica, with a distinct constriction in the region of PME, body and legs black with scattered orange reflective hairs. Palps black with white scales. Labium, endites and sternum all black. Clypeus short, black. Chelicerae vertical, black, grading to mid brown, with three large and two small promarginal teeth and two retromarginal teeth. White border on anterior third of dorsal abdomen. Unlike female, no pair of white patches on the dorsolateral edges of the abdomen. Ventral abdomen black with a scatter of small light markings. Spinnerets black. Spines (specimen damaged, after Galiano 1966): femur without spines, L1 tibia with two pairs of ventrolateral spines, L2–L4 tibia with two ventral spines and all metatarsi with two pairs of ventrolateral spines. Palp ( Figs 22–23 ): black, tibia with two small apophyses. Tegulum round, without lobe, embolus long and wound around tegulum, final section set in depression, tip bent. Dimensions: CL 1.67, EFL 0.74, CW 1.11, AEW 0.96, AMEW 0.62, PEW 0.96, SL 0.74.

Female: Similar in form to the male except abdomen mostly cream colour anteriorly with dark patches and covered with grey and white pennate hairs grading to black posteriorly and two pairs of distinct, large white patches on dorsolateral edges of the abdomen ( Fig. 18 ). Legs black with orange longitudinal stripes and orange tarsi. Epigynum ( Figs 20–21 ): lightly sclerotised. Spermatheca anterior to the fossa. Insemination ducts long and coiled, spermathecae subdivided into compartments ( Fig. 20 ). Dimensions: CL 1.98, EFL 0.93, CW 1.30, AEW 1.18, AMEW 0.74, PEW 1.18 SL 0.93, (P4+T4) 1.80.

Biology and distribution. Only known from three localities in Chile ( Fig. 24 ). The species appears to be an ant mimic resembling Camponotus .

Figures

FIGURES 18 – 25. Atmosphyrus tristiculus. 18 – 19 dorsal view (18 female, 19 male); 20 – 21 female genitalia (20 dorsal view of cleared specimen, 21 ventral view of external characteristics); 22 – 23 male palp (22 lateral view, 23 ventral view); 24 known distribution; 25 male chelicera (redrawn after Galiano 1987). Scales: total body 1 mm; remainder 0.2 mm