Mesabolivar catarinensis, 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 : 100-102

Mesabolivar catarinensis sp. n.

Figs 386–387 , 419–426 , 443–445

Diagnosis. Distinguished from known congeners by male procursus ( Figs 422–423 ; subdistal sclerotized process and bifid membranous tip), and by shape of epigynum ( Figs 424–425 , 443–444 ; anterior plate with posterior membranous indentation; pocket on sclerotized process); from most congeners also by armature of male chelicerae ( Figs 421 ; simple pair of apophyses close to median line, without proximal modification).

Etymology. The specific name is an adjective derived from the type locality.

Type material. BRAZIL: Santa Catarina: ♂ holotype, 1♀ paratype, UFMG (21524–25), 3♂ 2♀ paratypes, ZFMK (Ar 19189), São Joaquim National Park (28.034°S, 49.611°W), fern forest along small stream, ~ 1100–1200 m a.s.l., 18.x.2014 (B.A. Huber, L.S. Carvalho).

Other material examined. BRAZIL: Santa Catarina: 1♂ 1♀ 1 juv. in pure ethanol, ZFMK (Br 14-161), same data as types . 2♂, ZFMK ( Ar 19190), Serra Geral National Park, Churriado Canyon (29.137°S, 49.953°W to 29.130°S, 49.965°W), forest near river, 150–250 m a.s.l., 20.x.2014 (B.A. Huber, L.S. Carvalho) . 1♂ 2♀, ZFMK (Ar 19191), Serra Geral National Park , forest along road at ~ 1000 m a.s.l. (29.179°S, 50.024°W), 21.x.2014 (B.A. Huber, L.S. Carvalho) ; 3♀ 2 juvs in pure ethanol, ZFMK (Br 14-168), same data . 1♂ 1♀, ZFMK (Ar 19192), Serra Geral National Park , forest along road at ~ 700 m a.s.l. (29.182°S, 50.008°W), 21.x.2014 (B.A. Huber, L.S. Carvalho) . 2♂, ZFMK (Ar 19193), Aparados da Serra National Park, forest at northern margin of Itaimbezinho Canyon (29.159°S, 50.081°W), 940 m a.s.l., 22.x.2014 (B.A. Huber, L.S. Carvalho) ; 1♀ in pure ethanol, ZFMK (Br 14-176), same data .

Description. Male (holotype)

MEASUREMENTS. Total body length 5.0, carapace width 2.0. Distance PME-PME 160 µm, diameter PME 160 µm, distance PME-ALE 130 µm, distance AME-AME 40 µm, diameter AME 50 µm. Sternum width/length: 1.20/ 0.85. Leg 1: 56.0 (13.7 + 0.8 + 14.3 + 24.3 + 2.9), tibia 2: 9.7, tibia 3: 7.6, tibia 4: 9.3; tibia 1 L/d: 75. Femora 1–4 width (at half length): 0.26, 0.30, 0.29, 0.27.

COLOR (in ethanol). Carapace pale ochre-yellow with large dark median mark including ocular area, clypeus not darker; sternum orange; legs dark brown, without dark rings, tips of femora and tibiae lighter; abdomen greenish gray, with indistinct internal darker marks dorsally and laterally, ventrally small orange area in front of gonopore.

BODY. Habitus as in Fig. 386 ; ocular area slightly raised; carapace with distinct median furrow; clypeus unmodified; sternum unmodified.

CHELICERAE. With one pair of small, strongly sclerotized apophyses distally, close to median line, without proximal processes ( Fig. 421 ).

PALPS. As in Figs 419–420 , small relative to body size; coxa with retrolateral apophysis; trochanter barely modified; femur with retrolateral apophysis proximally, distally strongly widening; procursus with distinctive distal processes: subdistal sclerotized process with tiny side branch and bifid membranous tip ( Figs 422–423 ); genital bulb with large tapering process partly sclerotized.

LEGS. Without spines and curved hairs, few vertical hairs; retrolateral trichobothrium on tibia 1 at 2%; prolateral trichobothrium present on tibia 1; tarsus 1 with>40 pseudosegments, distally fairly distinct.

Male (variation). Tibia 1 in nine other males: 13.3–15.5 (mean 14.1). Procursus of males from Serra Geral and Aparados da Serra National Parks with slightly larger bifid membranous tip.

Female. In general similar to male; legs often lighter. Tibia 1 in five females: 8.9–12.8 (mean 11.5). Epigynum as in Figs 424–425 , 443–444 , relatively small; anterior plate with distinctive whitish area (indentation) and elevated median process with pocket; posterior plate relatively large. Internal genitalia as in Figs 426 , 445 , with pair of roughly triangular pore-plates and distinctive posterior arc.

Natural history. The spiders were found in domed webs in sheltered cavities near the ground. When disturbed, they started swinging and moved back into the protective shelter.

Distribution. Known from two localities in Santa Catarina state ( Brazil) ( Fig. 737 ).

Figures

FIGURES378–389. Live specimens,Mesabolivar iguazugroup.378–379.M.chapeco sp. n., male and female from Chapecó. 380–381. M. yucuma sp. n., male and female from Turvo. 382–383. M. iguazu Huber, 2000, males from Iguaçú. 384–385. M. charruaMachado etal., 2013, male andfemale from Serra Geral. 386–387.M.catarinensis sp. n., male and female from Serra Geral.388–389. M. bicuspis sp. n., male and female from St. Hilaire/Lange.

FIGURES 419–426. Mesabolivar catarinensis sp. n. (ZFMK Ar 19189). 419–420. Left male palp, prolateral and retrolateral views.421.Male chelicerae, frontalview. 422–423. Tip of left procursus, prolateral-ventral and retrolateral-dorsal views. 424– 425. Epigynum, lateral and ventral views. 426. Cleared female genitalia, dorsal view. Scale lines: 0.5 (419–421, 424–426), 0.3 (422–423).

FIGURES 433–446. Female epigyna in ventral and lateral views and cleared female genitalia in dorsal views, Mesabolivar iguazu group. 433.M. chapeco sp. n. (ZFMK Ar 19175). 434–436. M.yucuma sp. n. (ZFMK Ar 19176). 437–438. M.iguazu Huber, 2000 (ZFMK Ar 19181). 439–440. M. charrua Machado et al., 2013 (ZFMK Ar 19184). 441–442. M. argentinensis (Mello-Leitão, 1938) (MACN Ar 20050). 443–445. M. catarinensis sp. n. (ZFMK Ar 19189). 446. M. bicuspis sp. n. (ZFMK Ar 19194).

FIGURES 736–737. Known distribution of the Mesabolivar iguazu group. TL, type locality. “?”: dubious northern records of M. uruguayensis in Machado et al. (2013) (cf. Huber 2015:60).