Mesabolivar saci, 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 : 112-115

Mesabolivar saci sp. n.

Figs 452–453 , 489–497 , 531

Diagnosis. Easily distinguished from most congeners by subdistal lateral constriction of male chelicerae ( Fig. 492 ); also by details of male palp (procursus S-shaped in dorsal view, Fig. 491 ; femur very large relative to tibia, Figs 489–490 ), and by shape of epigynum ( Figs 494–496 ; anterior plate with pair of large processes, median pocket, and small median anterior process); from the very similar M. constrictus by tip of procursus in dorsal view (compare Figs 491 , 499 ), by proximal anterior processes on male chelicerae (compare Figs 493 , 500 ), and by pair of epigynal processes only weakly curved backwards (compare Figs 495 , 504 ).

Etymology. The species is named for a character in Brazilian folklore (Saci) who grants wishes to anyone who manages to trap him (I did!); noun in apposition.

Type material. BRAZIL: Santa Catarina: ♂ holotype, 1♀ paratype, UFMG (21532–33), 1♂ 3♀ paratypes, ZFMK (Ar 19207), São Joaquim National Park (28.034°S, 49.611°W), fern forest along small stream, ~ 1100–1200 m a.s.l., 18.x.2014 (B.A. Huber, L.S. Carvalho).

Other material examined. BRAZIL: Santa Catarina: 2♀ 1 juv. in pure ethanol, ZFMK (Br14-160), same data as types.

Description. Male (holotype)

MEASUREMENTS. Total body length 2.0, carapace width 1.0. Distance PME-PME 90 µm, diameter PME 80 µm, distance PME-ALE 70 µm, distance AME-AME 20 µm, diameter AME 30 µm. Sternum width/length (in other male; sternum in holotype damaged): 0.70/0.50. Leg 1: 8.5 (2.2 + 0.3 + 2.3 + 3.4 + 0.3; see variation below), tibia 2: 1.6, tibia 3: 1.3, tibia 4: 2.3; tibia 1 L/d: 26. Femora 1–4 width (at half length): 0.18, 0.20, 0.22, 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. 452 ; ocular area raised; carapace with shallow but distinct median furrow; clypeus unmodified; sternum unmodified.

CHELICERAE. With pair of large frontal apophyses and two pairs of smaller processes, one frontal, one lateral; with distinctive subdistal constriction ( Figs 492–493 ).

PALPS. As in Figs 489–490 ; coxa with large retrolateral apophysis; trochanter ventrally protruding; femur large, with retrolateral process proximally; tarsus with simple dorsal process; procursus S-shaped in dorsal view ( Fig. 491 ), with distinctive distal sclerotized and membranous elements; bulb with simple process distally divided in two parallel cylinders, one slightly sclerotized, the other transparent.

LEGS. Without spines and curved hairs, few vertical hairs; retrolateral trichobothrium on tibia 1 at 9%; prolateral trichobothrium present on tibia 1; tarsus 1 with only 5 pseudosegments (see variation below).

Male (variation). The distal segments of the only leg 1 of the holotype have unusual (probably teratological) lengths (metatarsus too long, tarsus too short); leg 1 in other male: 8.6 (2.2 + 0.3 + 2.3 + 3.1 + 0.7); tarsus 1 in this male with ~15 pseudosegments, distally fairly distinct.

Female. In general similar to male ( Fig. 453 ). Tibia 1 in four females: 1.8, 1.8, 1.9, 2.0. Epigynum as in Figs 494–496 ; complex anterior plate with small anterior median process, large median pocket, and pair of large processes weakly curved backwards; posterior plate anteriorly raised, with variably distinct median process at posterior margin. Internal genitalia as in Figs 497 , 531 , small relative to external genitalia, with pair of oval poreplates close together (pore-plates appear round in Fig. 497 because they are higher anteriorly than posteriorly). One female with whitish abdomen.

Natural history. This species was found among dense roots of ferns in the soil. One egg sac contained ~ 10 eggs.

Distribution. Known from type locality in Santa Catarina state ( Brazil) only ( Fig. 739 ).

Figures

FIGURES 447–458. Live specimens, Mesabolivar difficilis group (part 1). 447–448. M. itajai sp. n., male and female from Itajaí.449–451.M.niteroi sp. n., males and female from St.Hilaire/Lange. 452–453. M.saci sp. n., male and female from São Joaquim. 454–456. M. constrictus sp. n., males (regular color and white abdomen morph) and female from Três Barras. 457– 458.M.sepitus sp. n., male and female from Serra Geral.

FIGURES 489–493. Mesabolivar saci sp. n. (ZFMK Ar 19207). 489–490. Left male palp, prolateral and retrolateral views. 491. Left procursus, dorsal view. 492–493. Male chelicerae, frontal and lateral views. Scale lines: 0.5 (489–490), 0.3 (491– 493).

FIGURES 494–497. Mesabolivar saci sp. n. (ZFMK Ar 19207). 494–496. Epigynum, ventral, lateral, and frontal views. 497. Cleared female genitalia, dorsal view.Scale lines:0.3.

FIGURES 520–537. Female epigyna in various views and cleared female genitalia in dorsal views, Mesabolivar difficilis group. 520. M. itajai sp. n. (ZFMK Ar 19197). 521. M. niteroi sp. n. (ZFMK Ar 19198). 522–524. M.difficilis (Mello-Leitão, 1918) (ZFMK Ar 19201), epigyna in lateral, frontal, and posterior (slightly ventral) views. 525–530. M. sp. (“M. difficilis” in Bonaldo et al. 2009) from Presidente Figueiredo (525–527, ZFMK Ar 19205) and from Manaus (528–530, SMNK-ARA 12794) (522–530 at same scale and in same views). 531. M. saci sp. n. (ZFMK Ar 19207). 532. M. constrictus sp. n. (ZFMK Ar 19208). 533. M. sepitus sp. n. (ZFMK Ar 19210). 534–537. M. cavicelatus Machado et al., 2007 (epigyna: ventral views), from Penedo (534–535, ZFMK Ar19215) and from Ubatuba (536–537, ZFMK Ar 19218).

FIGURES 498–505. Mesabolivar constrictus sp. n. (ZFMK Ar 19208). 498, 500. Male chelicerae, frontal and lateral views. 499. Left procursus, dorsal view. 501–504. Epigynum, ventral, posterior, frontal, and lateral views. 505. Cleared female genitalia, dorsal view.Scale lines:0.3.

FIGURES 738–739. Known distribution of the Mesabolivar difficilis group.