Mecolaesthus longipes Huber 2020, sp. nov.
Creators: name: Huber, Bernhard A.
name: Villarreal, Osvaldo
Publisher: name: Zenodo
Year: 2020
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Arachnida
Araneae
Pholcidae
Mecolaesthus
Mecolaesthus longipes

description: Mecolaesthus longipes Huber sp. nov.
urn:lsid:zoobank.org:act: DD35F224-3961-418C-9F19-564124C806E3
Figs 384–385, 399–409, 421–423, 1043
Diagnosis
Distinguished from congeners by combination of: armature of male chelicerae (Figs 407–408; pair of large, rounded frontal processes set with many hairs, 5–7 of them very short and strong, and 3–4 small modified hairs more distally on weakly sclerotized area; very similar to M. bienmesabe Huber sp. nov.); by shape of procursus (Figs 401–403; small but distinct retrolateral process; distinctive pair of membranous distal processes, wider than in M. bienmesabe Huber sp. nov. and curved); by shapes of distal bulbal sclerites (short and wide median sclerite; arrow in Fig. 404); by epigynum (Fig. 421; large whitish area with small brown plate narrowing posteriorly) and internal female genitalia (Figs 409, 422–423; frame–like sclerite; wing-like anterior sclerites).
Etymology
The species name (Latin: long-legged) refers to the long legs of this species compared with other congeners at the same localities; adjective.
Type material
VENEZUELA – Mérida • ♂ holotype, ZFMK (Ar 21915), Mucuy, along Laguna El Suero trail (between 8.629° N, 71.039° W and 8.623° N, 71.034° W), ~ 2400–2600 m a.s.l., 24 Nov. 2018 (B.A. Huber, O. Villarreal M.).
Other material examined
VENEZUELA – Mérida • 3 ♂♂, 1 ♀, and 1 ♀ abdomen, ZFMK (Ar 21916), and 1 ♂, 2 ♀♀ (1 ♀ abdomen transferred to ZFMK, Ar 21916) in pure ethanol, ZFMK (Ven18-224), same collection data as for holotype • 1 ♀, ZFMK (Ar 21917), and 1 ♂ in pure ethanol, ZFMK (Ven18-231), Monte Zerpa, forest above La Hechicera (between 8.634° N, 71.163° W and 8.639° N, 71.167° W), 2050–2180 m a.s.l., 26 Nov. 2018 (B.A. Huber, O. Villarreal M., N.A. Sánchez G.) • 1 ♀, ZFMK (Ar 21918), and 1 ♂, 1 ♀ in pure ethanol, ZFMK (Ven18-227), El Valle, cloud forest along river (8.703° N, 71.077° W), 2650 m a.s.l., 25 Nov. 2018 (B.A. Huber, O. Villarreal M.) • 5 ♂♂, 6 ♀♀, 1 juv., ZFMK (Ar 21919-20), and 1 ♂, 2 ♀♀ in pure ethanol, ZFMK (Ven20-113), forest near La Carbonera (8.6276° N, 71.3688° W), 2380 m a.s.l., 8 Feb. 2020 (B.A. Huber, O. Villarreal M., Q. Arias C.) • 1 ♂, 1 ♀, 1 juv., ZFMK (Ar 21921), and 1 ♀, 2 juvs in pure ethanol, ZFMK (Ven20-128), between Tovar and Guaraque (8.2578° N, 71.7184° W), 2490 m a.s.l., forest along stream, 11 Feb. 2020 (B.A. Huber, O. Villarreal M., Q. Arias C.).
Description
Male (holotype)
MEASUREMENTS. Total body length 4.7, carapace width 1.8. Distance PME–PME 140 µm; diameter PME 130 µm; distance PME–ALE 110 µm; distance AME–AME 30 µm; diameter AME 20 µm. Leg 1: 50.5 (12.4 +0.5+12.0 + 22.3 +3.3), tibia 2: 7.3, tibia 3: 5.9, tibia 4: 6.8; tibia 1 L/d: 92; tibia 1-4 diameters: 130 µm, 170 µm, 180 µm, 160 µm.
COLOR (in ethanol). Carapace pale gray with wide median dark band including ocular area and pair of wide lateral marginal dark bands; clypeus with wide median brown band; sternum ochre with brown marginal bands; leg 1 brown, legs 2–4 ochre, with very indistinct darker bands on femora subdistally and tibiae proximally; abdomen pale greenish gray, dorsally and laterally with many dark bluish marks, ventrally with small dark mark in gonopore area, dark brown book lung covers, brown plate anteriorly close to pedicel, and bluish internal marks in front and behind gonopore area.
BODY. Habitus as in Fig. 384. Ocular area moderately raised. Carapace slightly inflated posteriorly, with shallow but distinct thoracic groove. Clypeus unmodified. Sternum wider than long (1.00/0.85), unmodified. Abdomen slightly elongate, pointed at spinnerets.
CHELICERAE. As in Figs 407–408, with pair of large, partly whitish frontal processes set with 6–7 modified hairs each, and pair of sclerotized plates slightly more distally with 3–4 modified hairs each.
PALPS. As in Figs 399–400; coxa with retrolateral apophysis, trochanter with small ventral process, femur proximally with large retrolateral apophysis, distally with prominent rounded ventral process, retrolateral trichobothrium of tibia in very distal position; procursus (Figs 401–403) at basis with bifid dorsal process, with small retrolateral apophysis, distally with pair of membranous processes; genital bulb complex (Figs 404–406), distally mostly membranous/whitish, with distinctive distal sclerites.
LEGS. Without spines and curved hairs; few vertical hairs; retrolateral trichobothrium of tibia 1 at 3%; prolateral trichobothrium present on all leg tibiae; tarsus 1 with ~45 pseudosegments, distally distinct.
Male (variation)
Tibia 1 in nine males (incl. holotype): 10.7–12.3 (mean 11.4); carapace inflation varying from indistinct to moderate; color of sternum variable, sometimes monochromous pale to whitish; anterior plate ventrally on abdomen sometimes absent, indistinct, or divided into two distinct plates.
Female
In general similar to male (Fig. 385) but smaller, carapace never inflated, abdomen never with anterior ventral plate, leg 1 not brown but same color as other legs, dark rings on legs slightly more distinct. Tibia 1 in 12 females: 7.6–8.9 (mean 8.2). Epigynum (Fig. 421) large whitish area with small brown plate narrowing posteriorly. Internal genitalia (Figs 409, 422–423) with distinctive frame–like sclerite, pore plates and median receptacle tilted towards the front.
Distribution
Known from several localities in the Venezuelan state Mérida (Fig. 1043).
Natural history
At Mucuy and Monte Zerpa, this species was found in large sheltered spaces such as hollow tree trunks. Near La Carbonera and between Tovar and Guaraque the large weakly domed webs (diameter ~ 40 cm) were more exposed, attached to large rocks or tree trunks. When disturbed, the spiders started to vibrate.
description: Published as part of Huber, Bernhard A. & Villarreal, Osvaldo, 2020, On Venezuelan pholcid spiders (Araneae, Pholcidae), pp. 1-317 in European Journal of Taxonomy 718 on pages 117-120, DOI: 10.5852/ejt.2020.718.1101, http://zenodo.org/record/4069574