Mesabolivar sepitus

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: 117-120

publication ID

https://doi.org/10.11646/zootaxa.4395.1.1

publication LSID

lsid:zoobank.org:pub:B43C234D-45C4-4A6D-9836-8A7524A5B291

persistent identifier

http://treatment.plazi.org/id/160AC713-C600-FFF2-2A9C-9FEE321C7EE4

treatment provided by

Plazi

scientific name

Mesabolivar sepitus
status

sp. n.

Mesabolivar sepitus  sp. n.

Figs 457–458View FIGURES 447–458, 506–515View FIGURES506–511View FIGURES 512–519, 533View FIGURES 520–537

Diagnosis. Easily distinguished from most similar known species ( M. beckeri  ; see Note below) by modifications of male chelicerae ( Figs 510–511View FIGURES506–511; median pair of apophyses much longer); also by male pedipalp ( Figs 506–507, 509View FIGURES506–511; shape of procursus: ventral process, distal and prolateral flaps), and by shape of epigynum ( Figs 512–514View FIGURES 512–519; anterior plate strongly elevated, with pair of indistinct humps and anterior pocket). From all other known congeners also by massive procursus partly wrapped around weakly sclerotized process of genital bulb.

Note. This species is very similar in several respects to a species originally described as Teuia beckeri Huber, 2000  . The proximal palpal segments are almost identical (femur much larger than tibia; tibia distally strongly projecting on retrolateral-ventral side), both species share the unique procursus partly wrapped around the weakly sclerotized process of the genital bulb, and both species share two pairs of processes proximally on the male chelicerae (compare Figs 506–511View FIGURES506–511 and Huber 2000: figs 1259–1262). Teuia beckeri  was placed in its own genus because the main putative synapomorphies of Mesabolivar  were missing: the median epigynal pocket and the corresponding pair of male cheliceral apophyses close to the median line. The species newly described here clearly shows both of these characters. Molecular data (Eberle et al., unpublished data; see Appendices 1–2) place M. sepitus  in the difficilis  group of Mesabolivar  . As a consequence, the monotypic genus Teuia Huber, 2000  is here synonymized with Mesabolivar González-Sponga, 1998  , and the type species is transferred accordingly: Mesabolivar beckeri (Huber, 2000)  , n. comb.

Etymology. The specific name refers to the bulbal process being enveloped or enwrapped by the procursus (Latin sepitus  = confined, hedged, surrounded); adjective.

Type material. BRAZIL: Santa Catarina: ♂ holotype, 1♀ paratype, UFMGAbout UFMG (21536–37), 4♂ 13♀ paratypes, ZFMKAbout ZFMK (Ar 19209–10), Serra Geral National Park, Churriado Canyon (29.137°S, 49.953°W), forest near river, 150 m a.s.l., 20.x.2014 (B.A. Huber, L.S. Carvalho).

Other material examined. BRAZIL: Santa Catarina: 3♀ in pure ethanol, ZFMKAbout ZFMK (Br 14-164), same data as type material  . 3♂ 6♀, ZFMK (Ar 19211), 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); 3♀ in pure ethanol, ZFMKAbout ZFMK (Br 14-169), same data  .

Description. Male (holotype)

MEASUREMENTS. Total body length 3.0, carapace width 1.3. Distance PME-PME 120 µm, diameter PME 120 µm, distance PME-ALE 110 µm, distance AME-AME 20 µm, diameter AME 30 µm. Sternum width/length: 0.95/ 0.60. Leg 1: 24.1 (6.1 + 0.5 + 6.4 + 9.6 + 1.5), tibia 2: 3.9, tibia 3: 3.2, tibia 4: 4.8; tibia 1 L/d: 67. Femora 1–4 width (at half length): 0.17, 0.16, 0.35, 0.13. Tibiae 3 also clearly thicker than other tibiae.

COLOR (in ethanol). Carapace ochre-yellow with slightly darker radiating marks, brown around ocular area; sternum light brown; legs ochre-brown, without dark or light rings; abdomen dorsally and laterally densely covered with bluish marks, ventrally with large light brown area in front of gonopore, without darker area in front of spinnerets.

BODY. Habitus as in Fig. 457View FIGURES 447–458; ocular area raised; carapace with distinct median furrow; clypeus and sternum unmodified.

CHELICERAE. As in Figs 510–511View FIGURES506–511; with two pairs of processes proximally: one pair of long pointed apophyses with curved tips near median line and one pair of shorter processes with rounded tips laterally.

PALPS. As in Figs 506–507View FIGURES506–511; coxa with large retrolateral apophysis; trochanter barely modified; femur very long, proximally slender with retrolateral process, distally widened; tibia much smaller than femur, distally strongly projecting on retrolateral-ventral side; tarsus with small dorsal process; procursus with large prolateral flap partly wrapped around bulbal process, distally with membranous and sclerotized elements ( Fig. 509View FIGURES506–511); genital bulb with simple weakly sclerotized process ( Fig. 508View FIGURES506–511).

LEGS. Densely covered with short hairs, without spines and curved hairs, few vertical hairs; retrolateral trichobothrium on tibia 1 at 3.5%; prolateral trichobothrium present on tibia 1; tarsus 1 with ~25 pseudosegments, distally fairly distinct.

Male (variation). Tibia 1 in seven other males 5.7–6.6 (mean 6.2).

Female. In general similar to male ( Fig. 458View FIGURES 447–458) but all femora (and tibiae) approximately same width. Tibia 1 in 19 females: 4.2–4.7 (mean 4.5). Epigynum as in Figs 512–514View FIGURES 512–519; anterior epigynal plate simple, protruding, with anterior pocket and pair of indistinct humps; posterior plate with pair of anterior sclerites, lighter median area and posterior wide sclerotized margin. Internal genitalia as in Figs 515View FIGURES 512–519, 533View FIGURES 520–537, with pair of oval pore-plates converging anteriorly.

Natural history. The spiders were found in small cavities in the ground, under dead wood and among the basis of bromeliad leaves. When disturbed, they ran a small distance and vibrated rapidly with small amplitude. Distribution. Known from two neighboring sites in Serra Geral National Park, Santa Catarina state ( Brazil) ( Fig. 739View FIGURES 738–739).

UFMG

Universidade Federal de Minas Gerais

ZFMK

Zoologisches Forschungsmuseum Alexander Koenig

Kingdom

Animalia

Phylum

Arthropoda

Class

Arachnida

Order

Araneae

Family

Pholcidae

Genus

Mesabolivar