Ibotyporanga xakriaba 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 : 55-59

Ibotyporanga xakriaba Huber sp. nov.

urn:lsid:zoobank.org:act:EFDAB528-2060-4D13-823D-5F3245131923

Figs 42 , 47–50

Diagnosis

Males are easily distinguished from most known congeners (except I. xique sp. nov.) by general shape of procursus ( Fig. 48A–C ; short and wide, distally with semitransparent ventral flap), by very short palpal patella ( Fig. 47C ; dorsally clearly shorter than medially wide), and by short conical prolateral process on embolus (arrow in Fig. 48D ); from similar I. xique by unique dorsal process on procursus (arrow in Fig. 48C ) and by dorsal protrusion distally on palpal femur (arrow in Fig. 47A ); males further distinguished from most known congeners (except I. xique and I. itatim sp. nov.) by slender legs (tibia 1 L/d>15). Females are distinguished from most known congeners by trapezoidal epigynum with triangular pocket and posterior lateral parts heavily sclerotized ( Fig. 50A ; similar in I. xique and I. itatim ); females of I. xique are possibly indistinguishable morphologically.

Etymology

The species name honors the Xakriabá, an indigenous people of Brazil who in pre-colonial times lived in the valley of the Tocantins River, in Goiás and along the São Francisco River; noun in apposition.

Type material

Holotype

BRAZIL – Piauí • ♂; Guaribas, Parque Nacional da Serra das Confusões ; 9.2257° S, 43.4630° W; 720 m a.s.l.; 13 Dec. 2010; L.S. Carvalho et al. leg.; CHNUFPI 1121 .

Paratypes

BRAZIL – Piauí • 2 ♂♂; same collection data as for holotype; CHNUFPI 1132 • 2 ♂♂; same locality as for holotype; 9–15 Dec. 2010; L.S. Carvalho et al. leg.; CHNUFPI 1134 • 1 ♂; same collection data as for preceding; CHNUFPI 1447 .

Other material examined

BRAZIL – Piauí • 1 ♂; Cristino Castro, Parque Nacional da Serra das Confusões ; 8.9380° S, 43.8634° W; 335 m a.s.l.; 9 Dec. 2012; L.S. Carvalho et al. leg.; CHNUFPI 1168 • 1 ♀; same collection data as for preceding; CHNUFPI 1170 • 1 ♀; same collection data as for preceding; UFMG 15694 • 1 ♂; Guaribas, Parque Nacional da Serra das Confusões ; 8.9756° S, 43.8181° W; 345 m a.s.l.; Dec. 2012; L.S. Carvalho et al. leg.; CHNUFPI 3737 • 1 ♀; same collection data as for preceding; CHNUFPI 3745 • 1 ♀; same collection data as for preceding; CHNUFPI 3755 • 1 ♂, 2 ♀♀, 1 juv.; Corrente, near Rio Corrente ; 10.4751° S, 45.1433° W; 455 m a.s.l.; 20 Jul. 2023; A. Galleti-Lima et al. leg.; CHNUFPI 5025 .

Assigned tentatively (no males available)

BRAZIL – Piauí • 1 ♀; Coronel José Dias, Parque Nacional Serra da Capivara ; 8.7672° S, 42.5600° W; 520 m a.s.l.; Apr. 2012; L.S. Carvalho leg.; CHNUFPI 371 • 1 ♀; same collection data as for preceding; CHNUFPI 396 • 1 ♀; São Raimundo Nonato, Parque Nacional da Serra da Capivara , Baixão das Andorinhas ; 8.8625° S, 42.6873° W; 485 m a.s.l.; 15 Jul. 2023; L.S. Carvalho and E.G. Noetzold leg.; CHNUFPI 5012 .

Description

Male (holotype)

MEASUREMENTS. Total body length 2.1, carapace width 0.97. Distance PME–PME 80 µm; diameter PME 85 µm; distance PME–ALE 50 µm; distance AME–AME 20 µm; diameter AME 70 µm. Leg 1: 7.40 (2.10+0.37 +2.00 +2.43 + 0.50), tibia 2: 1.77, tibia 3: 1.33, tibia 4: 1.92; tibia 1 L/d: 18; diameters of leg femora 0.20–0.21, of leg tibiae 0.11.

COLOUR (in ethanol). Prosoma ochre-orange, carapace medially slightly darker; legs ochre-yellow with indistinct darker rings distally on femora and tibiae; abdomen greenish-gray, dorsally and laterally with darker internal marks; ventrally with indistinct ochre-yellow plates in front of gonopore and in front of spinnerets.

BODY. Habitus as in I. xique sp. nov. (cf. Fig. 25H ). Ocular area slightly raised. Carapace with distinct but shallow thoracic groove. Clypeus with sclerotized rim with median notch. Sternum wider than long (0.66/0.56), with pair of rounded anterior processes near coxae 1, ~30 µm high, ~90 µm diameter at basis. Abdomen globular.

CHELICERAE. As in Fig. 49A–B ; with strongly curved median frontal apophysis; stridulatory files fine but well visible in dissecting microscope.

PALPS. As in Fig. 47 ; coxa unmodified; trochanter with short rounded ventral protrusion; femur proximally with distinct retrolateral process directed toward distal, with prolateral stridulatory pick, distally widened with distinctive dorsal protrusion; femur-patella joints not shifted toward one side; patella much shorter than wide, with distal ventral protruding rim; tibia almost globular, with proximal ventral process; tibia-tarsus joints not shifted toward one side; tarsus without dorsal process; procursus ( Fig. 48A–C ) relatively short, with light prolateral band, distinctive dorsal process, distally with ventral membranous process; genital bulb ( Fig. 48D–F ) with wide prolateral sclerite on bulbous part, with short conical prolateral process on embolus.

LEGS. Without spines but with longer and slightly stronger hairs ventrally on femora; without curved hairs; with several rows of short vertical hairs on tibia 1; retrolateral trichobothrium of tibia 1 at 66%; prolateral trichobothrium absent on tibia 1; tarsus 1 with ~4–5 pseudosegments, distally fairly distinct.

Variation (male)

Dark marks on carapace and legs variably distinct, some males also with proximal rings on leg tibiae. Tibia 1 in eight males (incl. holotype): 1.72–2.23 (mean 1.97). Retrolateral trichobothrium of tibia 1 in two other males at 53% and 60%, respectively.

Female

In general, similar to male but clypeus and sternum unmodified; tibia 1 with few short vertical hairs. Tibia 1 length in five females from Parque Nacional da Serra das Confusões and from Corrente: 1.53– 1.73 (mean 1.63). Epigynum ( Fig. 50A ) anterior plate trapezoidal, with deep anterior pocket, posterior lateral parts heavily sclerotized, posterior margin with pair of lateral indentations and with or without darker marks at median side of these indentations; posterior plate short and wide. Internal genitalia ( Figs 49C , 50B–F ) very short, with pair of very narrow pore plates, with small sclerotized and larger membranous lateral pockets.

The three females from Parque Nacional Serra da Capivara have externally identical epigyna; they are assigned tentatively to this species because no males are available from this locality. Tibia 1 in two females: 1.33, 1.48 (missing in third female).

Distribution

Known from several localities in southern Piauí, Brazil ( Fig. 42 ).

Natural history

The specimens were collected on arenite rock fields, under rocks and dead logs and among small pebbles, in shrubby caatinga vegetation areas.

Figures

Fig. 42. Known geographic distribution of Brazilian species with plesiomorphic short procursus.

Fig. 47. Ibotyporanga xakriaba Huber sp. nov., male from Brazil, Piauí, Parque Nacional da Serra das Confusões, CHNUFPI 1134. Left palp, prolateral, dorsal, and retrolateral views (arrow: distinctive dorsal process on femur). Scale line: 0.3 mm.

Fig. 48. Ibotyporanga xakriaba Huber sp. nov., male from Brazil, Piauí, Parque Nacional da Serra das Confusões, CHNUFPI 1134. A–C. Left tarsus and procursus, prolateral, dorsal, and retrolateral views (arrow: distinctive dorsal process on procursus). D–F. Left genital bulb, prolateral, dorsal, and retrolateral views (arrow: distinctive process on embolus). Scale lines: 0.2 mm.

Fig. 49. Ibotyporanga xakriaba Huber sp. nov., male and female from Brazil, Piauí, Parque Nacional da Serra das Confusões. A–B. Male chelicerae, frontal and lateral views, CHNUFPI 1134. C. Cleared female genitalia, dorsal view, CHNUFPI 3745. Scale lines: 0.3 mm.

Fig. 50. Ibotyporanga xakriaba Huber sp. nov., females from Brazil, Piauí, Parque Nacional da Serra das Confusões. A. Abdomen, ventral view, CHNUFPI 3755. B–C. Cleared female genitalia, ventral and dorsal views, CHNUFPI 3745. D. Cleared female genitalia, ventral view, CHNUFPI 1170. E–F. Details of cleared female genitalia, CHNUFPI 3745 (E) and CHNUFPI 1170 (F). Scale lines: 0.2 mm.

Fig. 25. Ibotyporanga spp., live specimens, part one (cf. Figs 55, 73). A. I. ziruma Huber sp. nov., female with egg sac from Colombia, Magdalena, Santa Marta. B–C. I. walekeru Huber sp. nov., male from Colombia, La Guajira, S of Riohacha, and female with egg sac from Colombia, Cesar, ESE of Pueblo Bello. D–E. I. piojo Huber sp. nov., male and female with egg sac from Colombia, Atlántico, near Piojo. F–G. I. itatim Huber sp. nov., male and female with egg sac from Brazil, Bahia, W of Itatim. H–I. I. xique Huber sp. nov., male and female with egg sac from Brazil, Bahia, S of Xique-Xique.