Ibotyporanga tuxa Huber, 2024

Huber, Bernhard A., Meng, Guanliang, Král, Jiří, Ávila Herrera, Ivalú M. & Carvalho, Leonardo S., 2024, Diamonds in the rough: Ibotyporanga (Araneae, Pholcidae) spiders in semi-arid Neotropical environments, European Journal of Taxonomy 963, pp. 1-169 : 123-128

Ibotyporanga tuxa Huber sp. nov.

urn:lsid:zoobank.org:act:7CF18804-6D45-45AC-9FA6-F0BB03C4028E

Figs 73E , 96 , 105–108

Diagnosis

Males are easily distinguished from known congeners by long process on palpal tarsus (arrow in Fig. 106C ) and by wide distance between main and dorsal branches of procursus ( Fig. 106C ); also by widened tip of dorsal branch of procursus ( Fig. 106A–C ). Females differ from known congeners by shape of epigynum ( Fig. 108A–C ; triangular rather than trapezoidal or oval, with distinct posterior indentation) and by internal sclerite with long stalk ( Figs 107D , 108D–G ).

Etymology

The species name honors the Tuxá, an indigenous people of Brazil that lives in Bahia; noun in apposition.

Type material

Holotype

BRAZIL – Bahia • ♂; W of Barra do Mendes, Ipupiara , at BA-046; 11.794° S, 42.288° W; 810 m a.s.l.; bare rock field with scattered shrubs; 21 Nov. 2022; B.A. Huber and A.S. Michelotto leg.; CHNUFPI 5956.

Paratypes

BRAZIL – Bahia • 1 ♂, 7 ♀♀; same collection data as for holotype; CHNUFPI 5957 • 1 ♂, 1 ♀; same collection data as for holotype; UFMG 31659 • 1 ♂, 1 ♀; same collection data as for holotype; CHNUFPI 9047 [deposited in ZFMK Ar 24378] • 2 ♂♂; same locality as for holotype but 250 m NW; 11.7930° S, 42.2901° W; 765 m a.s.l.; 25 Aug. 2016; L.S. Carvalho and B. T. Faleiro leg.; CHNUFPI 3669, 3776 • 5 ♀♀; same collection data as for preceding; CHNUFPI 3696, 3716, 3717, 3738, 3756 • 3 ♀♀; same collection data as for preceding; CHNUFPI 3795 .

Other material examined

BRAZIL – Bahia • 1 ♂ 10 ♀♀, in pure ethanol; same collection data as for holotype; CHNUFPI 5958 [deposited in ZFMK Br22-204; two female abdomens transferred to ZFMK Ar 24378] .

Assigned tentatively (no males available)

BRAZIL – Bahia • 1 ♀; NW of Ibipeba ; 11.540° S, 42.170° W; 590–640 m a.s.l.; hillside with scattered trees and thorny shrubs; 22 Nov. 2022; B.A. Huber and A.S. Michelotto leg.; CHNUFPI 5959 • 1 ♀, without legs, possibly mislabeled; São Desiderio , inside Gruta dos Noivos; 12.4166° S, 45.0749° W; 555 m a.s.l.; 28 Aug. 2016; L.S. Carvalho and B. T. Faleiro leg.; CHNUFPI 3659 .

Description

Male (holotype) MEASUREMENTS. Total body length 2.3, carapace width 0.85. Distance PME–PME 60 µm; diameter PME 75 µm; distance PME–ALE 20 µm; distance AME–AME 25 µm; diameter AME 45 µm. Leg 1: 4.65

(1.20+0.30 +1.25 +1.45 + 0.45), tibia 2: 1.05, tibia 3: 1.00, tibia 4: 1.45; tibia 1 L/d: 11; diameters of leg femora 0.21–0.22, of leg tibiae 0.10–0.11.

COLOUR (in ethanol). Prosoma and legs light ochre, leg femora and tibiae distally slightly darkened; abdomen pale gray with indistinct darker internal marks; ventrally with light ochre plates in front of gonopore and in front of spinnerets.

BODY. Habitus as in Fig. 73E . Ocular area slightly raised. Carapace with distinct but shallow thoracic groove. Clypeus with thick sclerotized rim with median notch ( Fig. 107A ). Sternum slightly wider than long (0.56/0.52), with pair of very low and indistinct anterior humps near coxae 1. Abdomen globular.

CHELICERAE. As in Fig. 107B–C ; with long median frontal apophysis; stridulatory files very fine and poorly visible in dissecting microscope.

PALPS. As in Fig. 105 ; coxa unmodified; trochanter with short ventral process; femur proximally with distinct retrolateral process directed toward distal, with prolateral stridulatory pick, distally widened but unmodified; femur-patella joints not shifted toward one side; patella dorsally ~1.9 × as long as medially wide; tibia with two trichobothria in relatively proximal position; tibia-tarsus joints barely shifted toward retrolateral side; tarsus with distinct finger-shaped dorsal process; procursus ( Fig. 106A–C ) with long dorsal branch widely separated in lateral view from main branch; dorsal branch slightly flattened (wider in dorsal view than in lateral view) and distally S-shaped, with widened and sclerotized tip; main procursus branch with light prolateral band, distally slender and transparent; genital bulb ( Fig. 106D–F ) with prolateral sclerite on bulbous part, embolus with dorsal ridge curved towards prolateral.

LEGS. Without spines but with longer and slightly stronger hairs ventrally on femora; without curved hairs; apparently without short vertical hairs; retrolateral trichobothrium of tibia 1 at 60%; prolateral trichobothrium absent on tibia 1; tarsus 1 with ~4–5 indistinct pseudosegments.

Variation (male)

Tibia 1 in six males (incl. holotype): 1.10–1.30 (mean 1.20).

Female

In general, similar to male but slightly darker (prosoma and legs mostly light brown rather than light ochre), carapace medially darker, ocular area and clypeus darker, leg femora and tibiae distally not darkened; slightly larger than males (total body length ~2.5) and with slightly longer legs: tibia 1 in 21 females: 1.25–1.55 (mean 1.42); sternum unmodified. Epigynum ( Fig. 108A–B ) anterior plate roughly triangular with rounded edges, posterior margin indented, with wide and shallow anterior pocket; posterior plate large but simple. Internal genitalia ( Figs 107D , 108D–E ) with pair of narrow pore plates posteriorly, median sclerite with long posterior stalk, and very thin-walled large membranous expandable sac.

The females from NW of Ibipeba and from São Desiderio are assigned tentatively because no males are available from these localities; the female from NW of Ibipeba has slightly shorter legs (tibia 1: 1.15); all legs are missing in the female from São Desiderio. The epigyna of both females appear indistinguishable from those of topotypical females ( Fig. 108C ); the same is true for the cleared genitalia of the female from São Desiderio ( Fig. 108F–G ; the female from NW of Ibipeba was not cleared).

Distribution

Known from type locality in Brazil, Bahia, and from two further localities ~ 30 km NNE and 310 km E, respectively, of the type locality ( Fig. 96A ); however, the specimens (only females) from the latter two localities are assigned tentatively. The female from São Desiderio is possibly mislabeled.

Natural history

At the type locality, the spiders were found under stones lying on a large rock plateau with very sparse vegetation. Females were very abundant and did either not move upon turning the stone or ran a short distance and quickly stopped when reaching a small depression on the stone. Males appeared less abundant and were much quicker at escaping. Many females were carrying an egg sac. Nine egg sacs from the type locality were round but slightly flattened, had diameters of 1.8–2.6, and egg diameters of 0.54–0.60; the total number of eggs per egg sac was ~30–40.

Figures

Fig. 73. Ibotyporanga spp., live specimens, part three (cf. Figs 25, 55), all from Brazil. A. I. sertao Huber sp. nov., male from Pernambuco, W of Orocó. B–C. I. guanambi Huber sp. nov., male and female with egg sac from Bahia, N of Guanambi. D. I. emekori Huber & Brescovit, 2003, male from Bahia, near Toca do Índio.E. I. tuxa Huber sp. nov., male from Bahia, W of Barra do Mendes. F. I. kiriri Huber sp. nov., male from Bahia, SE of Paramirim. G. I. ouro Huber sp. nov., male from Bahia, E of Gentio do Ouro. H. I. canudos Huber sp. nov., male from Bahia, SW of Morro do Chapéu.

Fig. 96. Known geographic distribution of Brazilian species with long procursus, with dorsal branch on procursus, and with median sclerite in female internal genitalia. The figure is split in order to avoid too much overlap. The question mark denotes a possibly mislabeled female specimen of I. tuxa sp. nov.

Fig. 105. Ibotyporanga tuxa Huber sp. nov., male from Brazil, Bahia, W of Barra do Mendes, ZFMK Ar 24378. Left palp, prolateral, dorsal, and retrolateral views. Scale line: 0.3 mm.

Fig. 106. Ibotyporanga tuxa Huber sp. nov., male from Brazil, Bahia, W of Barra do Mendes, ZFMK Ar 24378. A–C. Left tarsus and procursus, prolateral, dorsal, and retrolateral views (bold arrow: distinctive dorsal process on tarsus). D–F. Left genital bulb, prolateral, dorsal, and retrolateral views. Abbreviation: db =dorsal branch of procursus. Scale lines: 0.3 mm.

Fig. 107. Ibotyporanga tuxa Huber sp. nov., male and female from Brazil, Bahia, W of Barra do Mendes, ZFMK Ar 24378. A. Male ocular area, clypeus, and chelicerae, oblique frontal view (arrow: clypeus notch).B–C. Male chelicerae, frontal and lateral views. D. Cleared female genitalia, dorsal view (asterisk: expandable membranous sac not drawn, cf. Fig. 108E). Scale lines: 0.3 mm.

Fig. 108. Ibotyporanga tuxa Huber sp. nov. A–C. Female abdomens, ventral views, females from Brazil, Bahia, W of Barra do Mendes (A–B), ZFMK Ar 24378, and from Bahia, São Desiderio (C), CHNUFPI 3659. D–E. Cleared female genitalia, ventral and dorsal views, same specimen as in B. F–G. Cleared female genitalia, ventral and dorsal views, same specimen as in C. Abbreviations: es=expandable membranous sac; sc =internal sclerite. Scale lines: 0.3 mm.