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

description: Mesabolivar baianus sp. n.
Figs 140, 153–155, 160–164, 191–193
Mesabolivar caipora: Huber 2015: 7, figs 24–25, 55–56 (misidentified females; see Notes below).
Mesabolivar togatus: Astrin et al. 2006: 444 (misidentified specimens from Taiobeiras only; see Notes below).
Diagnosis. Distinguished from most known congeners by armature of male chelicerae (Figs 153–155; two pairs of frontal apophyses, one oblique pair distally and one strongly projecting pair proximally), by shape of procursus (Figs 160–161; in general as in M. togatus, but membranous dorsal flap more distinct: arrow in Fig. 160), and shape of epigynum (Figs 162, 164; in lateral view like M. togatus, cf. Huber 2000: fig. 862; oval anterior plate with posterior margin divided into three lobes by whitish membrane); from the very similar M. togatus by details of distal cheliceral apophyses (smaller angle between outer margins in frontal view; clearly visible in lateral view; compare Figs 150–155), and by shapes of lobes on anterior epigynal plate (median lobe narrower; lateral lobes wider; compare Figs 156, 157 and 162, 164).
Etymology. The specific name is an adjective derived from the type locality.
Type material. BRAZIL: Bahia: ♂ holotype, 1♀ paratype, MNRJ (14309), 11♂ 11♀ paratypes, ZFMK (Ar 19031), Reserva Biológica de Una, ‘site 2’ (15°10.6’S, 39°03.5’W), ~ 50–100 m a.s.l., 4.x.2011 (B.A. Huber, A. Pérez-González, M. Alves Dias).
Other material examined. BRAZIL: Bahia: 2♂ 4♀, ZFMK (Ar 19032), same locality but ‘site 1’ (15°11.0’S, 39°04.7’W), ~ 70–100 m a.s.l., 4.x.2011 (B.A. Huber, A. Pérez-González, M. Alves Dias); 2♀ 5 juvs in pure ethanol, ZFMK (Br 11-171), same data, ‘sites 1 & 2’. 2♂ 2♀, ZFMK (Ar 19033), Reserva Ecológica da Michelin, ‘site 1’ (13°49.3’S, 39°11.9’W), ~ 140 m a.s.l., 5.x.2011 (B.A. Huber, A. Pérez-González, M. Alves Dias); 6♂ 10♀, ZFMK (Ar 19034), same locality but ‘site 2’ (13°50.5’S, 39°14.5’W), ~ 140 m a.s.l., 6.x.2011 (B.A. Huber, A. Pérez-González, M. Alves Dias); 2♀ in pure ethanol, ZFMK (Br 11-190), same data; 2♂ 1♀ in pure ethanol, ZFMK (Br 11-194), same data but ‘sites 1 & 2’. 2♂, ZFMK (Ar 19035), near Santa Teresinha, Reserva Jequitibá (12°52.19’S, 39°28.65’W), 530 m a.s.l., 13.v.2015 (B.A. Huber, L.S. Carvalho). 6♂ 11♀, ZFMK (Ar 19036), Parque Nacional do Pau Brasil, ‘site 1’ (16°28.2’S, 39°16.8’W), ~ 65 m a.s.l., 30.ix.2011 (B.A. Huber, A. Pérez- González, M. Alves Dias); 6♂ 12♀, ZFMK (Ar 19037), same locality but ‘site 2’ (outside park limits) (16°25.7’S, 39°21.1’W), ~ 60 m a.s.l., 1.x.2011 (B.A. Huber, A. Pérez-González, M. Alves Dias); 3♂ 3♀ in pure ethanol, ZFMK (Br 11-155), same data.
Assigned tentatively. BRAZIL: Bahia: 8♂ 3♀, ZFMK (Ar 19038), Reserva Particular do Patrimônio Natural Serra Bonita (15°23.3’–23.4’S, 39°33.7’–34.0’W), ~ 750–850 m a.s.l., 2–3.x.2011 (B.A. Huber, A. Pérez- González, M. Alves Dias); 2♂ 1♀ in pure ethanol, ZFMK (Br 11-163), same data. 10♀, ZFMK (Ar 12620) (erroneously assigned to M. caipora in Huber 2015), Mata de São João, building (12°27.7’S, 38°15.5’W), ~ 100 m a.s.l., 8.x.2011 (B.A. Huber, A. Pérez-González, M. Alves Dias).
Minas Gerais: 2♂ 1♀ in pure ethanol, ZFMK (G004), Taiobeiras [15.8°S, 42.22°W], iv.2002 (A.J. Santos).
Description. Male (holotype)
MEASUREMENTS. Total body length 4.8, carapace width 1.4. Distance PME-PME 160 µm, diameter PME 190 µm, distance PME-ALE 160 µm, distance AME-AME 30 µm, diameter AME 65 µm. Sternum width/length: 1.2/ 0.7. Leg 1: 71.3 (17.5 + 0.8 + 16.8 + 32.9 + 3.3), tibia 2: 12.0, tibia 3: 7.1, tibia 4: 11.2; tibia 1 L/d: 93. Femora 1– 4 width (at half length): 0.22, 0.24, 0.31, 0.22.
COLOR (in ethanol). Carapace ochre to light brown, with large dark brown median mark including posterior part of ocular area; sternum ochre-yellow; legs brown, tips of femora and tibiae lighter, indistinct darker rings on femora (subdistally) and tibiae (proximally and subdistally); abdomen greenish gray, dorsally and laterally densely covered with dark bluish marks, ventrally with light brown plate in front of gonopore, very indistinct plate in front of spinnerets.
BODY. Habitus as in Fig. 140, very similar to M. togatus (cf. Huber 2000: figs 851–852); ocular area raised; carapace with distinct median furrow; clypeus unmodified; sternum unmodified.
CHELICERAE. With two pairs of frontal apophyses, proximal pair strongly projecting, distal pair oblique, angle between outer margins ~70°, clearly visible in lateral view (Figs 153–154).
PALPS. In general as in M. togatus (cf. Huber 2000: figs 855–856); palps in these two species may be indistinguishable, but the membranous dorsal flap on the procursus appears to be consistently more distinct in M. baianus (arrow in Fig. 160).
LEGS. Without spines, without curved hairs, few vertical hairs; retrolateral trichobothrium on tibia 1 at 2.5%; prolateral trichobothrium present on tibia 1; tarsus 1 with>45 pseudosegments, distally distinct.
Male (variation). Tibia 1 in 34 other males: 14.7–18.4 (mean 16.4). Sternum often with orange color. Males from Serra Bonita and Taiobeiras with shorter proximal cheliceral apophyses (Fig. 155); specimens from these localities are therefore assigned tentatively.
Female. In general similar to male but all leg femora approximately same width. Tibia 1 in 50 females: 9.7– 13.5 (mean 12.0). Epigynum as in Figs 162, 164; anterior plate oval, posterior margin divided into three lobes by whitish membrane, median lobe narrow (about as wide as long); lateral lobes of similar shape; large but simple posterior plate. Internal genitalia as in Figs 163, 192, with pair of large pore-plates in roughly vertical lateral position, slightly diverging anteriorly.
Natural history. The spiders were found in large, rather flat sheet webs, mostly close to the ground in sheltered spaces among rocks and large trees, rarely higher up and more exposed.
Distribution. Widely distributed in Bahia state (Brazil), possibly ranging into Minas Gerais and Sergipe states (Fig. 726); some of the specimens identified as M. togatus in Machado (2007) (from Sergipe: Caverna dos Aventureiros and Laranjeiras; and Bahia: Central, “Abrigo Waldemar II” – precise locality not identified) may actually belong to this species (judging from ranges of examined specimens).
Notes. The females assigned erroneously to M. caipora in Huber (2015) are extremely similar to this species; they are thus tentatively assigned to it. However, the internal genitalia differ slightly (compare Huber 2015: figs 25 and 56 and Figs 163, 192 herein) and the legs of those specimens are consistently shorter (tibia 1: 7.3–9.5 vs. 9.7–13.5). In the absence of males from this locality (Mata de São João, Bahia), the identity of these females remains unclear.
The specimens from “Taisbeiras” (typo for Taiobeiras) identified as M. togatus in Astrin et al. (2006) closely resemble unambiguous M. baianus but are tentatively assigned to this species for the lack of males from this locality. Their genetic distance to specimens from São Paulo sequenced in Astrin et al. (2006) supports the distinction between M. togatus and M. baianus (CO1, raw p-distance: 6.6%, K2P-corrected: 7.0%).
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 pages 43-45, DOI: 10.11646/zootaxa.4395.1.1, http://zenodo.org/record/1202519