Stenophareus aonda Villarreal, DoNascimiento & Rodríguez, 2007

Manzanilla, Osvaldo Villarreal, Donascimiento, Carlos & Rodríguez, Carlos J, 2007, Two new species of the enigmatic genus Stenophareus (Opiliones: Laniatores: Stygnidae) from the Venezuelan Guiana Shield, Zootaxa 1471, pp. 43-51 : 44-46

Stenophareus aonda Villarreal, DoNascimiento & Rodríguez , sp. n.

Figs 1–7 , 15–17

Type material. Male holotype ( MHNLS IV- 230), Venezuela, Bolívar State, Auyán-tepui, 1650 m; 21 August 1992; leg. Giuliano Trezzi . Paratypes: 2 males ( MHNLS IV- 228, MHNLS IV- 229); 1 female ( MHNLS IV- 231); all collected together with the holotype.

Etymology. A name in apposition, in reference to the cave system Aonda Superior, where the types were collected.

Diagnosis. This species is distinguishable from the other two congeneric species by completely depigmented eyes and tegument (vs eyes and tegument with pigmentation), elongated pedipals (pedipalp length/ DSL: 5.98 vs 2.83 and 1.41 for S. guerreroi sp. n. and S. roraimus , respectively) and elongated legs (I/DSL: 6.23 vs 4.44 and 1.81; II/DSL: 17.67 vs 9.03 and 3.21; III/DSL: 9.8 vs 5.86 and 2.36; IV/DSL: 13.12 vs 7.5 and 3.17), dorsal scute rectangular (vs slightly wider between grooves I–II), genital opercle with a large and conspicuous tubercle (vs no tubercles on genital opercle) and anterior area of prosoma granular (vs smooth). The new species is further distinguished from S. guerreroi sp. n. by the disposition of basal setae of the penis (aligned vs not aligned) and from S. roraimus by the size of the spines on mesotergal area III (reduced to small tubercles in S. aonda sp. n. vs well-developed in S. roraimus ), absence of dorsal tubercles of coxa IV and ornamentation of femur IV (smooth vs with two ventral rows of tubercles).

Description of male (holotype). Dorsum ( Figs 1–2 ). Anterior margin of dorsal scute smooth, area behind it granular. Eye mounds widely separated from each other, adjacent to posterior margin of prosoma. Four mesotergal areas in dorsal scute. Mesotergal areas I and IV unarmed, II with a pair of granules, III with a pair of small tubercles. Posterior margin of dorsal scutum with several minute setiferous granules. Free tergites smooth. Coxae I–III each with two tubercles.

Venter. Coxa I with a median row of 6–7 tubercles and two distal tubercles; coxa II with a median row of 5–7 small granules and with 1–2 granules distally; coxa III with a median row of 3–4 setiferous granules, 2–3 anterior granules and two distal granules. Free sternites with rows of minute setae. Genital opercle with a large anterior tubercle ( Fig. 3 ).

Chelicera ( Fig. 2 ). Basichelicerite elongated and distally swollen. Fixed finger with five conspicuous and three inconspicuous teeth. Movable finger with a large proximal tooth followed by seven smaller teeth, the distal-most of them high and triangular.

Pedipalp ( Figs 5–6 ). Coxa with a dorsoproximal tubercle. Trochanter unarmed. Femur unarmed, straight and extremely long (DSL/pedipalpal femur length: 0.44), its distal region swollen and curved. Patella very long (DSL/pedipalpal patella length: 0.53) and distally swollen. Tibia elongated, ectal with iiIIii (3=4>1=2>5>6); mesal with IiiIi (4>1>3>5>2). Tarsus ectal with iiiIiiIiI (4>7>9>6=8>5>3=2>1); mesal with iIiIiIi (4=2>6>3>5=7>1).

Legs ( Fig. 7 ). Trochanters I–IV with minute dorsal granules. Femora I–IV with longitudinal rows of minute setiferous granules, III–IV each with two dorsodistal tubercles, the retrolateral one largest. Patellae I– III each with a distal tubercle; IV with two distal tubercles. Tibiae, metatarsi and tarsi I–IV unarmed. Tarsal articles cylindrical, long and without scopula. Claws subparallel and smooth. Tarsal process well-developed. Tarsal formula (from leg I to IV): 10(3)/-/6–7/7.

Penis ( Figs 15–17 ). Apex of truncus with three long basal setae aligned in an oblique row on each side. Ventral plate on each side with three long distal setae close to each other, plus one long seta situated more ventrally and one short seta intermediate to the group of three setae; lateral margins slightly concave; distal margin with a wide U-shaped cleft. Glans without dorsal process.

Coloration. Uniformly light yellowish brown, slightly darker on posterior border of prosoma and dorsal surface of leg coxae. Eyes depigmented. Pedipalp, tibiae, patellae, metatarsi and tarsi of legs lighter.

Female. As the male; no sexual dimorphism discernible.

Intraspecific variation. Mesotergal area II with 1–2 dorsolateral granules. Coxa I with 4–7 median tubercles ventrally and 1–2 tubercles dorsally. Distal tubercle on patellae I–III present or absent.

Figures

FIGURES 1 – 7. Stenophareus aonda sp. n., male holotype (1 – 3, 5 – 7), male paratype (4). 1. Dorsal scute: dorsal view. 2. Same: lateral view. 3. Genital opercle: external view. 4. Cheliceral fingers: frontal view (MHNLS IV- 228) 5. Right pedipalp: ectal view. 6. Same: mesal view. 7. Trochanter, femur and patella of right leg IV: dorsal view. Scale bars 1 millimeter.

FIGURES 15 – 20. Stenophareus aonda sp. n., male holotype (15 – 17); Stenophareus guerreroi sp. n., male holotype (18 – 20). 15, 18. Distal part of penis: lateral view. 16, 19. Same: dorsal view. 17, 20. Total penis: lateral view. Scale bars 500 micrometers.