Stenoterommata egric Ghirotto & Indicatti 2021, n. sp.
Creators: name: Ghirotto, Victor Morais
name: Guadanucci, José Paulo Leite
name: Indicatti, Rafael Prezzi
Publisher: name: Zenodo
Year: 2021
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Arachnida
Araneae
Nemesiidae
Stenoterommata
Stenoterommata egric

description: Stenoterommata egric Ghirotto & Indicatti, n. sp.
(Figs 1G, H; 18-22)
urn:lsid:zoobank.org:act: B04C1562-E4F5-478A-B836-FE850178AB6E
TYPE MATERIAL. — Holotype. Brazil • 1 ♂; Minas Gerais, Lima Duarte, Conceição do Ibitipoca, Ibitipoca mountain range; 21°41’14.7”S, 43°53’46.9”W; 11.I.2017; V. M. Ghirotto leg.; under stone, kept alive, became adult in 01.X.2017; CAD 780.
Paratypes. Brazil • 2 ♀; same data as the holotype; CAD (1 ♀ CAD 781, 1♀ CAD 782) • 8 ♂, 1♀; Parque Estadual do Ibitipoca; 21°42’55.4”S, 43°53’56.9”W; IX.1997; 1380 m a.s.l.; A. de Oliveira & B. M. Sousa leg.; sucupira area, collected with pitfall traps; IBSP (6 ♂, 1 ♀ IBSP 108383, 2 ♂ IBSP 108458).
ADDITIONAL MATERIAL EXAMINED. — Brazil • 39 ♂, 1 j; Minas Gerais, Lima Duarte, Conceição do Ibitipoca, Parque Estadual do Ibitipoca; 21°42’55.4”S, 43°53’56.9”W; 1380 m a.s.l.; IX.1997; A. de Oliveira & B. M. Sousa leg.; sucupira area, collected with pitfall traps; IBSP (2♂ IBSP 108377, 1♂ IBSP 108379, 1 ♂ IBSP 108380, 1 ♂ IBSP 108405, 1 ♂ IBSP 108407, 1♂ IBSP 108415, 4 ♂ IBSP 108431, 1 ♂ IBSP 108433, 1 ♂ IBSP 108434, 1♂ IBSP 108437, 9 ♂ IBSP 108448, 5♂ IBSP 108463, 1 ♂ IBSP 108465, 3 ♂ IBSP 108475, 2 ♂, 1 j IBSP 108476, 3♂ IBSP 108477-108479, 1 ♂ IBSP 108486, 1♂ IBSP 110531).
DIAGNOSIS. — Males of S. egric Ghirotto & Indicatti, n. sp. resembles those of S. pavesii, S. gugai, S. peri and S. bodoquena Ghirotto & Indicatti, n. sp. by the elongated and thicker embolus (Fig. 19 A-D, J); differ from S. pavesii by the thicker embolus, not curved at the tip (Fig. 19 A-D, J); from S. gugai, S. peri and S. bodoquena Ghirotto & Indicatti, n. sp. by the thicker embolus tip (Fig. 19 A-D, J). Females differ from S. gugai and S. pescador by the receptacula with shorter and thicker ducts (Fig. 21A, B); from those of S. arnolisei, S. iguazu and S. tenuistyla by having 2-3 receptacula on each side (Fig. 21A, B); from S. pavesii by the basal dome slight inclined outwards (Fig. 21A, B); from all remaining Stenoterommata species by the shorter and less sclerotized basal dome (Fig. 21A, B). Additionally, individuals can be distinguished from most species by the dark coloration in life (Fig. 1G, H) and by the greater size, both sexes averaging significantly larger than most species of the genus (Fig. 1, note scales).
ETYMOLOGY. — The specific epithet is an acronym taken from “Espeleo Grupo Rio Claro - EGRIC” which organized the expedition to Ibitipoca mountain range that led the first author to collect the type specimens, and in recognition of their efforts in the study and preservation of Brazilian caves.
DESCRIPTION
Male (holotype)
Color pattern: in life, chelicerae, carapace and legs black, abdomen dorsally yellowish brown with dark brown mottling forming a chevron with wide bands. Body covered by black setae (Fig. 1G); in ethanol, chelicerae, carapace (Fig. 18A) and legs reddish brown covered with black and golden setae. Sternum, maxillae and coxae reddish light brown (Fig. 18B). Abdomen dorsally yellowish brown with dark brown mottling forming a chevron with wide bands, densely covered with dark brown setae (Fig. 18C), and ventrally yellowish light brown with few posterior brown stains (Fig. 18D). Total length 15.35. Chelicerae 1.55 long, 1.36 wide (only left side). Carapace 7.56 long, 5.92 wide, with narrow, procurved fovea, 0.77 wide. Abdomen 6.24 long, 3.40 wide. Thoracic region slightly raised. Clypeus narrow, 0.05 long. Eye tubercle 0.78 long, 1.30 wide, slightly elevated. Anterior eye row recurved, posterior slightly recurved (Fig. 18A). Eye sizes: AME 0.34, ALE 0.42, PME 0.26, PLE 0.27. Chelicerae with 10 teeth in prolateral row (Fig. 19H), with c. 35 basal smaller teeth, rastellum weak formed by long thin setae (Figs 18B, 17H). Intercheliceral tumescence small with few setae on basal region (Fig. 19H). Labium 0.57 long, 1.13 wide, with 2 cuspules (Fig. 18B). Maxillae with 84/90 blunt cuspules on internal basal angle. Serrula weak (Fig. 19I). Sternum oval, 3.58 long, 2.92 wide. Labial sigilla distant from margin by c. 0.1 × it is length, larger than sternal sigilla. Sternal sigilla (Fig. 18B): anterior and medium of the same size, posterior c. 2 × larger; anterior and medium distant from margin by c. 0.5 × length, posterior c. 1× length. Measurements: palp: femur 3.68/ patella 2.29/ tibia 2.51/ cymbium 1.17/ total 9.65; legs: I: femur 6.32/ patella 3.69/ tibia 5.17/ metatarsus 4.68/ tarsus 3.66/ total 23.52; II: 6.03/ 3.38/ 4.30/ 5.26/ 3.10/ 22.07; III: 5.65/ 2.78/ 3.60/ 5.38/ 3.15/ 20.56; IV: 7.01/ 3.19/ 5.20/ 7.25/ 3.29/ 25.94. Spination: palp: femur: d0-0-2; tibia: r1sap; legs: femora:I: d0-0-0-2-2; II: d0-1r-1p-1r-2-2; III: d1-2-2-2; IV: d1-1p-0-2-2; patellae: I: p0-0-1; II: p0-1-1; III: p1-1-1, r0-1; tibiae: I: v3-0-1r-1p-2p ap + 1r megaspine (Fig. 19G), p0-1-1-0; II: v3-0-1r-1p-3ap, p0-1-1-0; III: d0-1, v3-2-3ap, p0-1-1-0, r0-1-1-0; IV: v4-2-3ap, p1-1, r1-1; metatarsi: I: d0-1p-0-1p, v0-1r-0-0-1ap; II: d0-1p-0-1p, v2-2-0-2ap, r0- 0-1-0; III: d1-1r-1p-2-0-2, v2-2-3ap, p1-1-0-1; IV: d2-2-1, v2-0-2-3ap, p1-1-1. Metatarsal preening combs: III: 5VR, 5VP; IV: 7VR, 7VP. Tarsi I-IV flexible (Fig. 19G, tarsus I). Scopulae on tarsi I-IV light and symmetric; I, II divided by 3 rows of thin setae; III, IV divided by 4 rows of thicker setae. Scopulae on full length of metatarsi I and on apical 1/5 of metatarsi II, both divided by 3 sparse rows; III, IV absent. STC large with double row of teeth: I: 9, 6, 4, 8; II: 8, 6, 6, 8; III: 8, 6, 7, 8; IV: 9, 7, 6, 7. ITC on tarsus IV. Tricobothria with rounded, elevated bases. Around 60 epiandric spigots. Four spinnerets (Fig. 18D): PMS 0.81 long, with pumpkiniform spigots on 2/3 apical. PLS: basal segment 1.19, median 0.71, apical triangular, 0.60 long, with band of pumpkiniform spigots on inner edge of all segments. Palp: cymbium with elongate dense setae, denser at tip (Fig. 19E, F); tibia ventrally with a shallow excavation on apical third (Fig. 19E, F); tibial excavation and basal region of tegulum with grooves (Fig. 19 A-D); bulb piriform, ventrally curved, with embolus thick, dorso-ventrally flattened, with c. 12 parallel keels (Fig. 19 A-D).
Female (paratype CAD 781)
Color pattern: in life as in male; in ethanol, chelicerae reddish dark brown, carapace (Fig. 20A) and legs reddish brown, covered with black and golden setae, Sternum, coxae, and maxillae slightly lighter than the carapace (Fig. 20B). Abdomen dorsally yellowish brown with dark brown mottling forming a chevron with wide bands (Fig. 20C), ventrally yellowish brown (Fig. 20D). Total length 25.01. Chelicerae 3.90 long, 2.65 wide (only left side). Carapace 9.35 long, 7.78 wide, with narrow, procurved fovea 1.10 wide. Abdomen 11.76 long, 7.69 wide. Thoracic region slightly raised. Clypeus narrow 0.24 long. Eye tubercle 1.14 long, 1.59 wide, slightly elevated. Anterior eye row slightly recurved, posterior slightly recurved (Fig. 20A). Eye sizes: AME 0.38, ALE 0.55, PME 0.39, PLE 0.35. Chelicerae with 11 teeth in prolateral row, with c. 35 basal smaller teeth, rastellum weak, formed by long thin setae (Fig. 20B). Labium 1.06 long, 1.92 wide, with 2 cuspules (Fig. 20B). Maxillae with c. 110 blunt cuspules on internal basal angle (Fig. 20B). Serrula weak. Sternum oval, 4.67 long, 4.32 wide. Labial sigilla distant from margin by c. 0.1 × its length, larger than anterior sternal sigilla. Sternal sigilla (Fig. 20B): anterior almost round, slightly smaller than medium; posterior c. 2 × larger; all distant from margin by c. 0.5 × length. Measurements: palp: femur 5.11/ patella 3.01/ tibia 3.43/ tarsus 3.16/ total 14.71; legs: I: femur 7.26/ patella 4.79/ tibia 5.09/ metatarsus 4.36/ tarsus 3.20/ total 24.70; II: 6.34/ 4.27/ 4.26/ 4.02/ 3.30/ 22.19; III: 5.48/ 3.22/ 3.30/ 4.51/ 2.48/ 18.99; IV: 7.46/ 4.01/ 5.45/ 6.40/ 2.62/ 25.94. Spination: palp: tibia: v2-1r-1p-4ap, p0-1-0; legs: femora: I, II: d1p sap; III: d0-0-2; patellae: I, II: p0-0-1; III: p1- 1-1, r0-1-0; tibiae: I: v1r-1r-2ap, p0-1-1-0; II: v1r-1r-2ap, p0-1-1-0; III: d0-1, v2-1r-2ap, p1-1, r-0-1-0; IV: v1-1-2ap, r1-1; metatarsi: I: v1r-0-1r ap; II: v1r-2-0-0-2ap, p0-1-0-0; III: d1r-1r-1p-2-0-2, v2-2-3ap, p1-1-1; IV: d0-1r-1p-2-0-2, v2-1p-1r-1p-0-3ap, p0-1-1. Metatarsal preening combs: III: 12VP, 12VR, joined; IV: 4VP, 8VR. Tarsi I, II rigid; III, IV flexible. Scopulae on tarsi I undivided; on tarsi II divided by 2 rows of sparse setae; III divided by 6 rows, IV by 8 rows; III, IV divided by thicker setae; palp and I, II dense and symmetric; III, IV moderate. Scopula on full lenght of metatarsi I, II, undivided; III, IV absent. STC with double row of teeth: I: 7, 5, 3, 5; II: 6, 4, 3, 7; III: 7, 5, 4, 6; IV: 6, 4, 4, 7. STC on legs III, IV, the latter larger. ITC on tarsus IV. Palpal claw with 5 teeth on promargin. Tricobothria with rounded, elevated bases. Four spinnerets (Fig. 20C, D): PMS 1.03 long, with pumpkiniform spigots on apical 2/3. PLS: basal segment 1.86, median 1.23, apical triangular, 0.81 long, with band of pumpkiniform spigots on inner edge of all segments. Spermathecae with 2 receptacula on the right side, 3 on the left side; very small basal dome, inclined outwards, sclerotized at the top, ducts very short, receptacula rounded (Fig. 21A).
VARIATION. — Females (n = 2): total length 25.24-28.74; carapace 9.35-9.92; maxillae with 100-110 cuspules. Spermathecae with 2-3 receptacula (Fig. 21B).
DISTRIBUTION. — Known only from Ibitipoca mountain range, Lima Duarte, Minas Gerais state, Brazil.
HABITAT. — This species inhabits different formations at the type locality. They were found in small forests patches of the Atlantic Forest biome in deeper soils and also savanna formations at the border of the main formation of the Ibitipoca mountain range. These forests patches penetrate and are surrounded by savannas of the Cerrado domain (Fig. 22A). In the Parque Estadual do Ibitipoca, all the specimens of S. egric Ghirotto & Indicatti, n. sp. were collected in similar habitats as for the holotype (Sousa & Cruz 2008: 261). Individuals of this species were seen (but not collected) at cave entrances in the Parque Estadual do Ibitipoca. NATURAL HISTORY
Individuals were found in burrows lined with dense silk underneath stones. The burrow constitutes of one or two entrances (Fig. 22B). Due to few opportunities of active search at night, it is not unlikely that individuals also construct burrows directly in the soil, as does several Stenoterommata species (e.g. S. neodiplornata Ghirotto & Indicatti, n. sp.). In the Parque Estadual do Ibitipoca, the specimens of S. egric Ghirotto & Indicatti, n. sp. were collected with pitfall traps by Sousa & Cruz (2008); they represented one of the most common mygalomorph species in the region (47♂, 1 ♀, 1 juv.), after Homoeomma montanum (Mello-Leitão, 1923) (153♂, 2♀, 2 juv.), Theraphosidae Thorell, 1869 and Idiops camelus (Mello-Leitão, 1937) (109♂, 1♀, 1 juv.), Idiopidae Simon,1889 (Sousa & Cruz 2008; R. P. Indicatti pers. obs.). Stenoterommata spiders, despite being a potential prey for small vertebrates, were not found within the stomach contents of the lizards Enyalius perditus Jackson, 1978 (Sousa & Cruz 2008). On the other hand, curiously, 13.33% (n = 4) of the sampled lizards had juveniles of the trapdoor spider genus Idiops Perty, 1833 in its stomach contents (Sousa & Cruz 2008). In addition, these lizards are diurnal, sleeping on the tip of the branches of shrubs and trees at night (Sturaro & Silva 2010), while juveniles and females of Idiops usually are nocturnal, living within trapdoor burrows (Indicatti 2013: figs 12, 13; Ferretti et al. 2017: fig. 3 b, c), making the encounter even more difficult. Probably encounters occurred at dusk, during which the two could be active. Although the Idiops have a nocturnal habit, some specimens can be found at dusk on the edge, or even entirely outside their burrows, as observed in several areas of Cerrado and Atlantic Forest in southeastern Brazil (R. P. Indicatti pers. obs.).
description: Published as part of Ghirotto, Victor Morais, Guadanucci, José Paulo Leite & Indicatti, Rafael Prezzi, 2021, The genus Stenoterommata Holmberg, 1881 (Araneae, Pycnothelidae) in the Cerrado and Atlantic Forest from Southeastern and Central Brazil: description of four new species, pp. 311-339 in Zoosystema 43 (17) on pages 332-338, DOI: 10.5252/zoosystema2021v43a17, http://zenodo.org/record/5008496