Cybaeolus Simon, 1884

Cybaeolus Simon, 1884 View in CoL

Cybaeolus Simon 1884: 125 (type species by monotypy Cybaeolus pusillus Simon, 1884 ); 1898: 244.

Mevianes Simon 1904: 110 (type species M. delfini Simon, 1904 , designated by Petrunkevitch (1928: 93). Synonymized by Lehtinen (1967: 226).

Clitistes Simon 1902: 20 (type species by monotypy Clitistes velutinus Simon 1902 ), synon. nov..

Diagnosis

Species of Cybaeolus resemble other hahniids by having a retrolateral hook-shaped tibial process with a groove through which (presumably) the embolus slides ( Fig. 15I–K View Figure 15 ), but are distinguished by having a retrolateral patellar process with two or more tips ( Fig. 15D View Figure 15 ), and spinnerets arranged in a group with the PMS posterior to the ALS ( Figs 3–6 View Figure 3 View Figure 4 View Figure 5 View Figure 6 ), instead of arranged in a line or having the PMS advanced in between the ALS.

Description

Small spiders (1.50–3.50) with eight eyes ( Fig. 15A View Figure 15 ), anterior eye row slightly procurved in anterior view, posterior row slightly procurved to straight in dorsal view, AME normally developed, PME separated by one diameter of PME, clypeus no greater than 2.5× diameter of AME. Colour patterns of prosoma, and especially of opisthosoma, extremely polymorphic ( Figs. 21A View Figure 21 , 22 View Figure 22 , 23A View Figure 23 , 24 View Figure 24 , 25D View Figure 25 , 26E View Figure 26 , 27 View Figure 27 ). Carapace light brown, with or without thoracic markings, without foveal furrow. Opisthosoma oval or elongate, it can be dark, pale, orange, or brown, mottled, with or without chevrons. Chelicerae with three or four promarginal and three retromarginal teeth, male with or without stridulatory file made of minute bumps, rastellum (a row of rake setae with thickened bases; Fig. 18C View Figure 18 ) present in females of C. delfini and C. rastellus , absent in C. pusillus . Endites not convergent, serrula in a transverse line ( Fig. 18B View Figure 18 ), posterior external margin variably inflated or projecting in males. Labium slightly wider than long, anterior edge straight, posterior slightly convex. Sternum shieldshaped, weakly concave anteriorly at base of labium. Male palp with simple retrolateral patellar apophysis with two or more distal thorns ( Fig. 15D View Figure 15 ), RTA acute, curved, furrowed, tip with regular teeth pointing backwards ( Figs 15I–K View Figure 15 ); a swollen area near the RTA base bears several thick setae. Cymbium oval, with retrolateral furrow leading to RTA ( Fig. 17J View Figure 17 ). Copulatory bulb with disc-shaped tegulum, with a membranous patch where the fleshy median apophysis arises in C. delfini and C. rastellus ; only the membranous patch present in C. pusillus . Embolus arising proximally from tegulum, rotating clockwise (left palp, ventral view).

Epigyne with paired copulatory openings, usually blocked with mating plugs ( Figs 17H View Figure 17 , 18G View Figure 18 ). Copulatory ducts long, leading to spherical spermathecae, fertilization ducts short, on posterior margin; accessory bulb unremarkable, restricted to small bump with gland ducts near the copulatory opening (observed only in C. rastellus ; Fig.18I View Figure 18 ). Spinnerets ( Figs 3–6 View Figure 3 View Figure 4 View Figure 5 View Figure 6 ) in relatively compact group, PLS 70–80° from ALS, PMS 40–50° from ALS. ALS conical with wide base, PLS and PMS cylindrical, PLS equal in length to ALS, distal segment of ALS very short; distal segment of PLS very short, PLS not extended, length equal to or smaller than ALS. Colulus as two patches of setae. Spigot morphology (examined with SEM in adults of C. pusillus and C. rastellus ): ALS with one major ampullate gland spigot flanked by a nubbin, and 10–18 piriform gland spigots. PMS with one minor ampullate gland spigot, two cylindrical gland spigots in female, from five to eight aciniform gland spigots. PLS with one cylindrical gland spigot in female, from six to 11 aciniform gland spigots. Tracheal spiracle wide, slightly separated from spinnerets, leading to two thick trunks, each ramifying in three bundles of tracheoles, all limited to opisthosoma (observed from dissection of C. rastellus ; Fig. 18E View Figure 18 ). Leg formula 1243. Spination: femora I with dorsal and prolateral spines, patellae with two dorsal spines, tibiae I and II with dorsal and prolateral spines, tibiae II and IV with dorsal, prolateral, ventral, and retrolateral spines, metatarsi III and IV with prolateral, retrolateral, and ventral spines. Trichobothria with longitudinal fingerprint striae on proximal plate ( Fig. 17F View Figure 17 ), arranged on tarsi d0-1-0 or d0-1- 1-0 ( Figs 17D View Figure 17 , 18D View Figure 18 ), metatarsi d0-1-0 and tibiae d0-1-0. Tarsal organ a simple keyhole ( Fig. 17G View Figure 17 ).

Composition

Three species: Cybaeolus pusillus , Cybaeolus rastellus , and Cybaeolus delfini .

Distribution

In temperate forests and shrublands of Chile, from Región de Antofagasta to Región de Magallanes, and adjacent Argentina, from Neuquén province to Tierra del Fuego province.