Isoctenus segredo, Polotow & Brescovit, 2009

Polotow, Daniele & Brescovit, Antonio D., 2009, Revision and cladistic analysis of Isoctenus and description of a new neotropical genus (Araneae, Ctenidae, Cteninae), Zoological Journal of the Linnean Society 155 (3), pp. 583-614 : 600

ISOCTENUS SEGREDO SP. NOV. ( FIG. 11A–D )

Type material: Male holotype from Usina Hidrelétrica de Segredo, Reservatório do Rio Jordão , Candói / Mangueirinha, Paraná, Brazil, 3.v.1996, R. Bertani, deposited in IBSP 7227. Paratypes : 1 female from the same locality and collector as holotype , 24.iv– 4.v.1996, deposited in IBSP 58386; 1 male and 1 female from the same locality and collector as holotype , 24.iv–4.v.1996, deposited in IBSP 58387.

Additional material examined: BRAZIL. Paraná: Candói / Mangueirinha, Usina Hidrelétrica de Segredo, Reservatório do Rio Jordão , 2 male, 6 females ( IBSP 7201–7203 , 8034 ) .

Etymology: The species epithet is a toponymy in apposition and it is a Portuguese noun meaning ‘secret’.

Diagnosis: Isoctenus segredo sp. nov. resembles I. charada sp. nov. by the morphology of the RTA in male palp ( Fig. 11A, B ), but can be distinguished by the short and slender median apophysis and the basal projection of embolus short in male palp ( Fig. 11A ) and by the subquadrangular median field, large lateral spurs and spermathecae with a reduced head and large base in the epigynum ( Fig. 11C, D ).

Description: Male (holotype). Coloration as in I. foliifer , except carapace with longitudinal lighter stripe from the eyes to the posterior margin and a lighter arrow mark on abdomen dorsum. Total length 9.80. Carapace 5.40 long and 3.90 wide. Clypeus 0.12 high. Eyes diameters: AME 0.18, ALE 0.14, PME 0.26, PLE 0.24. Leg measurements: I: femur 4.00/ patella 2.10/ tibia 4.40/ metatarsus 3.70/ tarsus 1.90/ total 16.10; II: 4.00/ 1.80/ 3.80/ 3.20/ 1.50/ 14.30; III: 3.60/ 1.60/ 3.40/ 3.20/ 1.50/ 13.30; IV: 4.80/ 1.90/ 4.80/ 5.00/ 1.90/ 18.40. Leg spination as in I. foliifer , except metatarsus I and II r1-1 p-1-1. Palp: tibia short, approximately half of the cymbium length; RTA with ventral branch conical and dorsal branch short and robust with internal grooves; tibia with short and curved ventral apophysis ( Fig. 11A, B ). Cymbium with conical ventral retrolateral projection and short dorsal retrolateral projection; short and laminar embolus with rounded tip; median apophysis with anterior and posterior projections short and conical ( Fig. 11A ).

Female ( IBSP 58386). Coloration as in male. Total length 12.30. Carapace 5.00 long and 4.10 wide. Clypeus 0.20 high. Eye diameters: AME 0.18, ALE 0.20, PME 0.26, PLE 0.24. Leg measurements: I: femur 4.00/ patella 2.20/ tibia 3.80/ metatarsus 3.00/ tarsus 1.40/ total 14.40; II: 3.90/ 1.80/ 3.60/ 2.80/ 1.40/ 13.50; III: 3.50/ 1.40/ 2.80/ 3.00/ 1.30/ 12.00; IV: 4.70/ 1.90/ 4.50/ 5.10/ 1.80/ 18.00. Leg spination as in I. foliifer , except tibia II p1-1. Epigynum: median field with anterior margin smooth and posterior margin slightly projected; lateral spurs not covered by the median field and with rounded tip ( Fig. 11C ). Ventral wall with a fold covering part of the spermathecae ( Fig. 11D ).

Variation: Three males: total length 8.30–8.90, carapace 4.40–4.60, femur I 4.00–4.10; seven females: total length 9.80–13.50, carapace 4.70–5.40, femur I 3.80–4.20.

Distribution: Southern Brazil, State of Paraná.

Figures

Figure 11. Isoctenus segredo sp. nov.: A, male palp, ventral view; B, male palp, retrolateral view; C, epigynum, ventral view; D, epigynum dorsal view. Scale bars: 0.50 mm.