Mesabolivar macushi, 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 : 24-29

Mesabolivar macushi sp. n.

Figs 90–97 , 104–105 , 128–129

Diagnosis. Easily distinguished from similar congeners ( M. aurantiacus , M. cyaneus , M. spinosus ) by shape of procursus ( Figs 96–97 ; short distal sclerite with small subdistal parallel side branch), by armature of male chelicerae ( Figs 92–93 ; pair of strongly curved, blade-shaped frontal apophyses), and by female external and internal genitalia ( Figs 94–95 , 128–129 ; epigynum without pocket, without processes; small pore-plates; weakly sclerotized median sac-like structure).

Etymology. The specific name honors the Macushi, an indigenous people living in eastern Venezuela, southern Guyana, and northern Brazil; noun in apposition.

Type material. VENEZUELA: Bolívar: ♂ holotype, ZFMK (Ar 18962), forest near base of Salto Angel (5°58.0’N, 62°31.7’W), ~ 720 m a.s.l., domed webs near ground, 7.xii.2002 (B.A. Huber).

Other material examined. VENEZUELA: Bolívar: 1♀ 2 juvs, together with holotype.

Description. Male (holotype)

MEASUREMENTS. Total body length 3.7, carapace width 1.7. Distance PME-PME 180 µm, diameter PME 170 µm, distance PME-ALE 120 µm, distance AME-AME 35 µm, diameter AME 50 µm. Sternum width/length: 1.15/ 0.85. Leg 1: 61.7 (14.7 + 0.7 + 14.1 + 27.9 + 4.3), tibia 2: 9.1, tibia 3: 6.8, tibia 4: 8.7; tibia 1 L/d: 88. Femora 1–4 width (at half length): 0.21, 0.23, 0.26, 0.23.

COLOR (in ethanol). Carapace ochre-yellow with large brown mark covering most of posterior half, ocular area brown, clypeus not darkened, sternum light brown; legs light brown, without dark or light rings; abdomen ochregray, with many dark internal marks dorsally and laterally, with small light brown plate in front of gonopore.

BODY. Habitus similar to M. aurantiacus (cf. Figs 78, 80 ); ocular area raised; carapace with distinct median furrow; clypeus and sternum unmodified.

CHELICERAE. With pair of strongly curved, blade-shaped frontal apophyses ( Figs 92–93 ) with finely granulated surface.

PALPS. As in Figs 90–91 ; coxa with retrolateral apophysis; trochanter with short rounded ventral process; femur with retrolateral apophysis proximally, widened distally; tarsus with three small dorsal processes; procursus S-shaped, short distal process with small subdistal parallel side branch ( Figs 96–97 ); genital bulb process slender, with weakly sclerotized bifid distal process ( Figs 104–105 ).

LEGS. Without spines and curved hairs, few vertical hairs; retrolateral trichobothrium on tibia 1 at 3%; prolateral trichobothrium present on tibia 1; tarsus 1 with ~60 pseudosegments, distally fairly distinct.

Female. In general similar to male; tibia 1: 12.4. Epigynum as in Figs 94 , 128 ; anterior plate without pocket, with very indistinct and shallow median furrow, lateral parts more heavily sclerotized but not elevated; in lateral view slightly protruding towards posterior edge; posterior plate large, simple. Internal genitalia as in Figs 95 , 129 , with small pore-plates, weakly sclerotized median sac.

Natural history. The spiders were collected from domed webs hidden in sheltered cavities of the ground. Distribution. Known from type locality in Bolívar state ( Venezuela) only ( Fig. 725 ).

Figures

FIGURES90–95.Mesabolivar macushisp. n. (ZFMK Ar18962).90–91.Leftmale palp, prolateral and retrolateral views.92– 93. Male chelicerae, lateral and frontal views. 94. Epigynum, ventral view. 95. Cleared female genitalia, dorsal view. Scale lines:0.5.

FIGURES96–103.Left procursi, prolateraland retrolateral views.96–97.Mesabolivar macushi sp.n.(ZFMK Ar 18962).98– 99. M. aurantiacus (Mello-Leitão, 1930) (ZFMK Ar 18963). 100–101. M. cyaneus (Taczanowski, 1874) (ZFMK Ar 18989). 102–103.M.spinosus (González-Sponga, 2005) (MIZA MAGS 1176). Scale line:0.5 (all at same scale).

FIGURES 104–114. Left bulbal processes, dorsal and prolatero-ventral views (104–111), epigynum, ventral and lateral views (112–113), andcleared female genitalia,dorsal view (114). 104–105.Mesabolivar macushi sp. n. (ZFMK Ar 18962).106–107. M. aurantiacus (Mello-Leitão, 1930) (ZFMK Ar 18963). 108–109. M.cyaneus (Taczanowski, 1874) (ZFMK Ar 18989). 110– 114.M.spinosus (González-Sponga, 2005) (MIZA MAGS 1176). Scale lines: 0.5 (all bubal processes at same scale).

FIGURES 128–137. Female epigyna in ventral and lateral views and cleared female genitalia, dorsal views, Mesabolivar aurantiacus group. 128–129. M. macushi sp. n. (ZFMK Ar 18962). 130–132. M. spinosus (González-Sponga, 2005) (MIZA MAGS 1176). 133–134. M. tabatinga sp. n. (ZFMK Ar 18992). 135–137. M. anseriformis (González-Sponga, 2011) (ZFMK, Ven02/100-14).

FIGURES 78–89. Live specimens and habitus photos, Mesabolivar aurantiacus group. 78–81. M. aurantiacus (Mello-Leitão, 1930), males from Tabatinga, Manaus, and Belém, female from Belém. 82–84. M. tabatinga sp. n., male, female, and mating pair from Tabatinga. 85–87. M. eberhardi Huber, 2000, males and female from Jamari. 88–89. M. anseriformis (González- Sponga, 2011), male in dorsal and lateral views (ZFMK Ar 19012).

FIGURES 724–725. Known distribution of the Mesabolivar aurantiacus ‘group’.TL, type locality.