Mesabolivar niteroi, 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 : 107-111

Mesabolivar niteroi sp. n.

Figs 449–451 , 481–487 , 521

Diagnosis. Easily distinguished from most known congeners by shape of male palp (very similar to M. itapoa , cf. Huber 2015: figs 193–194; wide femur; distinctive shape of procursus; genital bulb with slightly sclerotized process and long membranous side branch), by shape of male chelicerae ( Figs 481–482 ; distinctive pair of processes), by pair of posterior processes on female sternum, and by shape of epigynum ( Figs 484–486 ; distinctive processes on anterior plate; rows of stronger hairs on small sclerotized plates behind epigynum); from very similar M. itapoa by male chelicerae (apophyses much less projecting in lateral view, compare Fig. 482 and Huber 2015: fig. 198), by anterior epigynal plate (only one pair of processes in posterior view, compare Figs 486, 488 ); also by shorter processes on female sternum (<100 µm long vs. 150 µm in M. itapoa ).

Etymology. The specific name is derived from the type locality; noun in apposition.

Type material. BRAZIL: Paraná: ♂ holotype, 1♀ paratype, UFMG (21530–31), 2♂ 1♀ paratypes, ZFMK (Ar 19198), Saint-Hilaire/Lange National Park, forest along river above Fazenda Niteroi (25.657°S, 48.601°W), ~ 100 m a.s.l., 11.x.2014 (B.A. Huber, L.S. Carvalho).

Other material examined. BRAZIL: Paraná: 1♀ in pure ethanol, ZFMK (Br 14-130), same data as types ; 2♀, ZFMK (Ar 19199), and 1♀ in pure ethanol, ZFMK (Br 14-136), same data but night collecting . 1♂ 4♀, ZFMK (Ar 19200), Saint-Hilaire/Lange National Park, forest above Hotel Mata Atlântica (25.670°S, 48.600°W), ~ 200–300 m a.s.l., night collecting, 12.x.2014 (B.A. Huber, L.S. Carvalho); 1♀ in pure ethanol, ZFMK (Br 14-142), same data .

Description. Male (holotype)

MEASUREMENTS. Total body length 2.3, carapace width 1.05. Distance PME-PME 95 µm, diameter PME 110 µm, distance PME-ALE 80 µm, distance AME 25 µm, diameter AME 25 µm. Sternum width/length: 0.75/0.55. Leg 1: 21.3 (5.1 + 0.5 + 5.5 + 9.2 + 1.0), tibia 2: 3.4, tibia 3: 2.5, tibia 4: 4.4; tibia 1 L/d: 69. Femora 1–4 width (at half length): 0.17, 0.22, 0.20, 0.14.

COLOR. Carapace pale ochre, with darker margins and three pairs of darker radial lines, ocular area and clypeus also darker; sternum ochre-brown; legs ochre to light brown, without light or dark rings; abdomen greenish grey with dark bluish marks dorsally and laterally; genital plate in front of gonopore slightly darker.

BODY. Habitus as in Figs 449–450 ; ocular area raised; carapace with distinct median furrow; clypeus and sternum unmodified.

CHELICERAE. As in Figs 481–482 , with distinctive pair of wide frontal projections, similar M. itapoa but less projecting in lateral view.

PALPS. Very similar M. itapoa (see Huber 2015: figs 193–194), but proximal segments slightly stronger (femur maximum diameter 340 µm vs. 300 µm; tibia maximum diameter 240 µm vs. 210 µm); procursus slightly different in shape (compare Fig. 483 and Huber 2015: fig. 196; proximal ventral process larger, narrowing towards distal); bulbal process in dorsal view slightly different (distal sclerite narrower).

LEGS. Without spines and curved hairs, few vertical hairs; retrolateral trichobothrium on tibia 1 at 4.5%; prolateral trichobothrium present on tibia 1; tarsus 1 with>15 pseudosegments, distally distinct.

Male (variation). Tibia 1 in three other males: 4.7, 5.2, 5.6.

Female. In general similar to male ( Fig. 451 ) but sternum with pair of processes at posterior margin; processes not as long and slender as in M. itapoa (rather conical, 70–100 µm long, vs. 150 µm in M. itapoa ). Tibia 1 in eight females: 3.0–3.5 (mean 3.2). Anterior epigynal plate strongly protruding, with only one pair of short processes, without pocket but with strongly sclerotized plate on frontal side ( Figs 484–486 ); posterior plate narrow and weakly developed, with row of 3–4 stronger hairs on small sclerotized plates on each side. Internal genitalia as in Figs 487 , 521 , very small relative to epigynum, with tiny elongate pore-plates embedded in transversal sclerite.

Natural history. The spiders were found in small wet cavities in the ground. When disturbed, they vibrated with high frequency and small amplitude and eventually ran away quickly.

Distribution. Known from two neighboring sites in Saint-Hilaire/Lange National Park, Paraná state ( Brazil) only ( Fig. 438 ).

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 481–488. Mesabolivar niteroi sp. n. (481–487, ZFMK Ar 19198) and M. itapoa Huber, 2015 (488, ZFMK Ar 12645).481–482.Male chelicerae, frontal and lateral views. 483.Left procursus, retrolateral view.484–485.Epigynum, lateral and ventral,views.487. Cleared female genitalia, dorsal view.486, 488.Epigyna in posterior views.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 433–446. Female epigyna in ventral and lateral views and cleared female genitalia in dorsal views, Mesabolivar iguazu group. 433.M. chapeco sp. n. (ZFMK Ar 19175). 434–436. M.yucuma sp. n. (ZFMK Ar 19176). 437–438. M.iguazu Huber, 2000 (ZFMK Ar 19181). 439–440. M. charrua Machado et al., 2013 (ZFMK Ar 19184). 441–442. M. argentinensis (Mello-Leitão, 1938) (MACN Ar 20050). 443–445. M. catarinensis sp. n. (ZFMK Ar 19189). 446. M. bicuspis sp. n. (ZFMK Ar 19194).