Pikelinia arenicola, Lise, Arno A., Ferreira, Ana Carla K., Cruz, Estevam L. & Silva, Da, 2010

Lise, Arno A., Ferreira, Ana Carla K., Cruz, Estevam L. & Silva, Da, 2010, Description of a new species of Pikelinia (Araneae: Filistatidae) from Brazil, with notes on its ecology, Zootaxa 2604, pp. 61-68 : 62-67

Pikelinia arenicola sp. n.

Figs. 1–32

Type material: Holotype male from Viamão, Parque Estadual de Itapuã, Rio Grande do Sul, Brazil, 18.XI.2003, Ana Carla K. Ferreira ( MCTP 19721). Paratypes: same data as holotype, 1 Ƥ ( MCTP 17881); 1 3, 09.III.2004, ( MCTP 17854), 1 3, 26.VI.2004, ( MCTP 17860), 1 Ƥ, 17.XII.2003, ( MCTP 17857), 1 Ƥ, 30.IV.2004, ( MCTP 17863), all from the same locality and collector.

Etymology. The specific name is an adjective in apposition to the generic name and refers to the sandy habitat preferred by this species.

Diagnosis. Males of Pikelinia arenicola sp. n. resemble those of Pikelinia tambilloi ( Grismado & Ramírez, 2006: 40, figs. 1–11) by the similar shape of the palpal tibia, but can be distinguished by the tibia being larger, by the different curvature of the apex of the bulb ( Figs. 7, 8 ) and by a projection on the ventral face of the tarsus ( Figs. 7 , 14–16 ). Females can be distinguished by the shape of the epigastric flap with numerous marginal long feathery setae ( Fig. 6 ).

Description. Male (Holotype, MCTP 19721). Total length 2.22. Carapace 1.0 long, 0.70 wide, 0.40 high. Carapace elliptic, convex, narrower on the anterior region, with few bristles ( Figs. 1, 2 ). General color yellow, shaded with dark brown. Lateral margins bordered with brown. Clypeus 0.18 high. Eyes on mound. Ocular area black. Anterior eye row almost straight, posterior slightly recurved. Eye diameters and eye interdistances: AME 0.04, ALE 0.10, PME 0.08, PLE 0.08, AME-AME 0.04, AME-ALE tangent, PME-PME 0.06, PME- PLE close together. MOQ 0.16 long in dorsal view, anterior width 0.12, posterior width 0.18. Chelicerae 0.24 long, 0.10 wide, yellow, shaded with brown ( Fig. 13 ). Labium 0.20 long, 0.16 wide, yellow. Endites 0.34 long, 0.10 wide, convergent, light yellow, shaded with brown near the articulation with the palpus, coated with many bristles. Sternum 0.60 long, 0.50 wide, elliptic, yellow, shaded with brown, margins darker. Legs: formula 1.4.2.3; color – light gray shaded with brown. Leg II with curved metatarsus carrying retrolaterally a group of thick macrosetae ( Figs. 9, 10 , 17, 18 ). Tarsus curved with prominent claw ( Fig. 22 ). Leg measurements (length: femur, patella, tibia, metatarsus, tarsus, total): I: 1.64, 0.32, 1.90, 1.44, 0.80, 6.10; II: 1.24, 0.32, 1.20, 0.80, 0.40, 3.96; III: 0.86, 0.30, 0.74, 0.80, 0.50, 3.20; IV: 1.26, 0.34, 1.20, 1.16, 0.56, 4.52. Palpus yellow; femur long, with a longitudinal row of setae; tibia dilated with a dorsal-retrolateral apical projection, setose; cymbium short, almost spherical ( Figs. 7, 8 , 14–16 ). Abdomen ovoid ( Figs. 1, 2 ) 1.26 long, 0 70 wide, 0.70 high, dorsum cream with transversal parallel brown bands, sides cream, venter cream irregularly shaded with brown. Epigastric region light fulvous. Spinnerets light yellow. Tegument of dorsum covered with numerous white setae ( Figs. 11, 12 ), venter covered with long white setae.

Female (Paratype, MCTP 17881). Total length 3.06. Carapace 1.14 long, 0.90 wide, 0.40 high, shape as in male. Color light fulvous stained with brown; the shading is darker than in the male, lateral margins brown ( Fig. 3 ). Clypeus 0.18 high. Eyes as in male. Eye diameters and interdistances: AME 0.06, ALE 0.10, PME 0.06, PLE 0.10, AME-AME 0.04, AME-ALE tangent, PME-PME 0.06, PME-PLE tangent. MOQ 0.14 long in dorsal view, anterior width 0.14, posterior width 0.20. Chelicerae 0.22 long, 0.12 wide, light yellowish with the anterior face coated with brown setae. Labium 0.26 long, 0.22 wide, light fulvous, densely coated with setae. Endites 0.44 long, 0.14 wide on the apical third, very convergent, densely coated with setae. Sternum 0.64 long, 0.60 wide, light fulvous, shaded with brown, setose ( Fig. 4 ). Legs: formula 1.4.2.3; general color as in male. Female pedipalpi with prominent claw ( Fig. 21 ). Femur of leg IV slightly dilated ( Fig. 19 ) with feathery setae ( Fig. 20 ). Leg measurements (length: femur, patella, tibia, metatarsus, tarsus, total): I: 1.20, 0.36, 1.16, 1.04, 0.70, 4.46; II: 0.84, 0.36, 0.66, 0.66, 0.48, 3.00; III: 0.72, 0.34, 0.50, 0.60, 0.40, 2.56; IV: 1.02, 0.36, 0.90, 0.86, 0.50, 3.64. Abdomen ovoid, 1.90 long, 1.20 wide, 1.20 high, dorsum whitish cream with the same parallel stripes as in the male. Sides whitish cream, ventral face cream shaded with brown. Epigastric region light fulvous, epigastric flap with a row of marginal feathery setae ( Fig. 6 ). Spermathecae rounded ( Fig. 5 ). Female cribellum conspicuous ( Figs. 23, 24 ). Spinnerets whitish yellow, tegument soft, with long bristles ( Figs. 25–30 ).

Variation. Males (n=6). Total length 2.30 (2.00–2.53). Carapace length 1.01 (0.88–1.04), width 0.77 (0.70–0.82), height 0.59 (0.52–0.62). Abdomen length 1.28 (1.10–1.44), width 0.74 (0.64–0.84), height 0.69 (0.62–0.76). Females (n=6). Total length 3.00 (2.35–3.92). Carapace length 1.07 (0.92–1.34), width 0.84 (0.60–1.06), height 0.65 (0.46–0.80); abdomen length 1.92 (1.26–2.56), width 1.15 (0.82–1.60), height 0.92 (0.68–1.54).

Other material examined. BRAZIL: Rio Grande do Sul, Viamão, Parque Estadual de Itapuã, 2 Ƥ, 28.VIII.2003, ( MCTP 17.876), 3 3, 2 Ƥ, 17.XII.2003, ( MCTP 17.884), 1 3, 1 Ƥ, 02.XII.2003, ( MCTP 17.894), 1 3, 13.I.2004, ( MCTP 17.871), 5 3, 13.I.2004, ( MCTP 17.875), all collected by Ana Carla K. Ferreira.

Distribution. Known only from the type locality.

Ecological notes. During the study period 79 adult specimens of Pikelinia arenicola sp. n. were collected (61 males and 18 females). Forty-one specimens were collected within the dune area, 10 in the forest and 28 in the ecotone ( Fig. 31 ). This apparent preference for arid environments has also been documented for other Pikelinia species ( Ramírez & Grismado, 1997). Males were collected in almost every month of the year ( Fig. 32 ). Most males were collected between November 2003 and February 2004, coinciding with the end of the period of spring and summer ( Fig. 32 ). Twenty-four males, approximately 39% of all collected males, were captured in January ( Fig. 32 ).

Figures

FIGURE 31. Specimens of Pikelinia arenicola sp. n. collected in the different sampled areas at “ Parque Estadual de Itapuã ”, Viamão, Rio Grande do Sul, Brazil from July 2003 to June 2004.

FIGURE 32. Number of males and females of Pikelinia arenicola sp. n. collected at “ Parque Estadual de Itapuã ”, Viamão, Rio Grande do Sul, Brazil from July 2003 to June 2004.

FIGURES 1 – 10. Pikelinia arenicola sp. n.: 1, 2. male habitus (1 dorsally, 2 laterally). 3 – 6. female habitus (4 dorsally, 5 ventrally). 5, 6. female epigynum (5 spermathecae, dorsally, 6 epigastric flap, ventrally). 7, 8. male palpus (7 retrolaterally, 8 prolaterally). 9, 10. male left metatarsus II (9 retrolaterally, 10 ventrally).

FIGURES 11 – 18. Pikelinia arenicola sp. n.: 11, 12. male carapace (11 dorsally, 12 detail of setae). 13. chelicerae, posterior view; 14 – 16. left male palpus (14 retrolaterally, 15 retrolaterally (in detail), 16 prolaterally). 17, 18. male left metatarsus II (17 ventrally, 18 detail of setae).

FIGURES 19 – 26. Pikelinia arenicola sp. n.: 19, 20. female femur IV (20 detail of setae, 21. female pedipalpus). 22. detail of claw and setae of leg IV. 23, 24. female cribellum (23 cribellum, 24 detail of spigots). 25, 26. spinnerets (25 male, 26 female).

FIGURES 27 – 30. Pikelinia arenicola sp. n.: 27 – 30. spinnerets (27 male, anterior lateral, 28 female, posterior median, 29 male, posterior median, 30 female, posterior lateral).