Mesabolivar turvo, Huber, 2018

Huber, Bernhard A., 2018, The South American spider genera Mesabolivar and Carapoia (Araneae, Pholcidae): new species and a framework for redrawing generic limits, Zootaxa 4395 (1), pp. 1-178 : 121-123

Mesabolivar turvo sp. n.

Figs 466–469 , 538–544

Diagnosis. Distinguished from known congeners by shape of procursus ( Figs 539–540 ; slender with pointed tip), by armature of male chelicerae ( Figs 541–542 ; pair of frontal apophyses not close to median line), and shape of epigynum and internal female genitalia ( Figs 543–544 ; oval anterior plate without pocket and processes; very large posterior plate; distinctive internal structure connecting pore-plates).

Etymology. The specific name is derived from the type locality; noun in apposition.

Type material. BRAZIL: Rio Grande do Sul: ♂ holotype, 1♀ paratype, UFMG (21538–39), 2♂ 4♀ paratypes, ZFMK (Ar 19222), Turvo National Park, Lagoas Trail near headquarters (27.231°S, 53.849°W), 400 m a.s.l., 29.x.2014 (B.A. Huber, L.S. Carvalho).

Other material examined. BRAZIL: Rio Grande do Sul: 3♀ in pure ethanol, ZFMK (Br 14-199), same data as types . 1♀, ZFMK (Ar 19223), Turvo National Park , near Salto do Yucumã (27.136°S, 53.882°W), 175 m a.s.l., 28.x.2014 (B.A. Huber, L.S. Carvalho).

Paraná: 1♂ 1♀, ZFMK (Ar 19224), Iratí Forest Reserve (25.362°S, 50.584°W), 850 m a.s.l., 13.x.2014 (B.A. Huber, L.S. Carvalho) ; 2♀ in pure ethanol, ZFMK (Br14-145).

Description. Male (holotype)

MEASUREMENTS. Total body length 2.4, carapace width 1.0. Distance PME-PME 110 µm, diameter PME 90 µm, distance PME-ALE 70 µm, distance AME-AME 20 µm, diameter AME 30 µm. Sternum width/length: 0.75/ 0.50. Leg 1: 23.6 (6.0 + 0.4 + 6.1 + 9.5 + 1.6), tibia 2: 3.6, tibia 3: 2.4, tibia 4: 4.1; tibia 1 L/d: 76. Femora 1–4 width (at half length): 0.11, 0.21, 0.17, 0.12.

COLOR (in ethanol). Prosoma and legs ochre-yellow, carapace with dark median line, legs without light or dark rings; abdomen greenish-gray, dorsally and laterally densely covered with dark marks, ventrally pale with light brown mark in front of gonopore, without mark in front of spinnerets.

BODY. Habitus as in Figs 466–467 ; ocular area raised; carapace with shallow but distinct median furrow; clypeus unmodified; sternum unmodified.

CHELICERAE. With pair of strong frontal apophyses, tips of apophyses apparently with one modified hair each ( Figs 541–542 ).

PALPS. As in Figs 538–539 ; coxa with large retrolateral apophysis; trochanter barely modified; femur with retrolateral process proximally, distally widening; tibia very short; tarsus with two retrolatero-dorsal processes; procursus very simple, without processes, slender with pointed tip, in dorsal view slightly S-shaped ( Fig. 540 ); genital bulb with large process mostly whitish.

LEGS. Without spines and curved hairs, few vertical hairs; retrolateral trichobothrium on tibia 1 at 4%; prolateral trichobothrium present on tibia 1; tarsus 1 with>20 pseudosegments, distally fairly distinct.

Male (variation). Tibia 1 in three other males: 5.8, 5.8 (Turvo National Park), 4.8 (Iratí Forest Reserve).

Female. In general similar to male ( Figs 468–469 ) but femora 2 and 3 not thicker than others. Tibia 1 in six females from Turvo National Park: 3.8–4.4 (mean 4.0); in three females from Iratí Forest Reserve: 3.4, 3.7, 3.7. Epigynum as in Fig. 543 ; simple oval anterior plate, slightly protruding, internal sclerite visible through cuticle; posterior plate very large, simple, with dark internal mark medially. Internal genitalia as in Fig. 544 , with distinctive sclerite connecting pore-plates.

Natural history. The spiders were found in small cavities in the ground, often in the more humid places under dead branches. When disturbed, they ran a short distance and then stopped moving or vibrated very slightly.

Distribution. Known from two localities in Rio Grande do Sul and Paraná states ( Brazil) ( Fig. 738 ).

Figures

FIGURES 459–469. Live specimens, Mesabolivar difficilis group (part 2). 459. M. difficilis (Mello-Leitão, 1918), male from Rio das Pedras. 460–462. M. huberi Machado et al., 2007, male and female from Itajaí. 463–465. M. cavicelatus Machado et al., 2007, males and female from Penedo. 466–469. M. turvo sp. n., males and females from Iratí (466, 469) and Turvo (467– 468).

FIGURES 538–544. Mesabolivar turvo sp. n. (ZFMK Ar 19222). 538–539. Left male palp, prolateral and retrolateral views. 540. Left procursus, dorsal view. 541–542. Male chelicerae, lateral and frontal views. 543. Epigynum, ventral view. 544. Cleared female genitalia, dorsal view.Scale lines:0.3 (538–539, 541–544), 0.2 (540).

FIGURES 738–739. Known distribution of the Mesabolivar difficilis group.