Mesabolivar constrictus Huber 2018, sp. n.
Creators: name: Huber, Bernhard A.
Publisher: name: Zenodo
Year: 2018
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Arachnida
Araneae
Pholcidae
Mesabolivar
Mesabolivar constrictus

description: Mesabolivar constrictus sp. n.
Figs 454–456, 498–505, 532
Diagnosis. Easily distinguished from most congeners (except M. saci) by subdistal constriction of male chelicerae (Fig. 498); also by details of male palp (procursus S-shaped in dorsal view, Fig. 499; femur very large relative to tibia; cf. Fig. 490), and by shape of epigynum (Figs 501–504; anterior plate with pair of large processes, median pocket, and small median anterior process); from the very similar M. saci by tip of procursus in frontal view (compare Figs 491, 499), by absence of proximal anterior processes on male chelicerae (compare Figs 493, 500), and by pair of epigynal processes strongly bent backwards (compare Figs 495, 504).
Etymology. The specific name refers to the unusual constriction in the male chelicerae (Latin constrictus = compressed, squeezed, contracted); adjective.
Type material. BRAZIL: Santa Catarina: ♂ holotype, 1♀ paratype, UFMG (21534–35), 3♂ 4♀ paratypes, ZFMK (Ar 19208), Três Barras National Forest (26.242°S, 50.301°W), 800 m a.s.l., 14.x.2014 (B.A. Huber, L.S. Carvalho).
Other material examined. BRAZIL: Santa Catarina: 5♀ in pure ethanol, ZFMK (Br14-146), same data as types.
Description. Male (holotype)
MEASUREMENTS. Total body length 1.8, carapace width 0.87. Distance PME-PME 80 µm, diameter PME 80 µm, distance PME-ALE 60 µm, distance AME-AME 20 µm, diameter AME 25 µm. Sternum width/length: 0.67/ 0.47. Leg 1: 8.8 (2.0 + 0.3 + 2.1 + 3.0 + 0.7), tibia 2: 1.4, tibia 3: 1.1, tibia 4: 2.1; tibia 1 L/d: 23. Femora 1–4 width (at half length): 0.18, 0.24, 0.24, 0.17.
COLOR (in ethanol). Prosoma and legs ochre-yellow, legs without light or dark rings; abdomen dorsally and laterally densely covered with dark bluish marks, ventrally pale greenish gray with light brown marks in front of gonopore and in front of spinnerets.
BODY. Habitus as in Fig. 454; ocular area raised; carapace with shallow but distinct median furrow; clypeus unmodified; sternum unmodified.
CHELICERAE. With pair of strong frontal processes and distinctive subdistal constriction (Figs 498, 500).
PALPS. In general very similar to M. saci (cf. Figs 489–490); only procursus in dorsal view clearly different (Fig. 499).
LEGS. Without spines and curved hairs, few vertical hairs; retrolateral trichobothrium on tibia 1 at 8.5%; prolateral trichobothrium present on tibia 1; tarsus 1 with ~15 pseudosegments, distally fairly distinct.
Male (variation). Tibia 1 in three other males: 2.0, 2.1, 2.1. One male with whitish abdomen (Fig. 455).
Female. In general similar to male. Tibia 1 in five females: 1.6–1.9 (mean 1.8). Epigynum as in Figs 501–504; complex anterior plate with small anterior median process, median pocket, and pair of large processes strongly bent backwards; posterior plate anteriorly raised. Internal genitalia as in Figs 505, 532, very small relative to external genitalia, with pair of round pore-plates close together.
Natural history. The spiders were found in relatively humid places under logs and branches on the ground, in tiny webs built in small holes in the ground. One egg sac contained ~ 10 eggs.
Distribution. Known from type locality in Santa Catarina state (Brazil) only (Fig. 739).
description: Published as part of Huber, Bernhard A., 2018, The South American spider genera Mesabolivar and Carapoia (Araneae, Pholcidae): new species and a framework for redrawing generic limits, pp. 1-178 in Zootaxa 4395 (1) on page 115, DOI: 10.11646/zootaxa.4395.1.1, http://zenodo.org/record/1202519