Ariadna Audouin 1826
Creators: name: Giroti, André Marsola
name: Brescovit, Antonio Domingos
Publisher: name: Zenodo
Year: 2018
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Arachnida
Araneae
Segestriidae
Ariadna

description: Genus Ariadna Audouin, 1826
Ariadna Audouin, 1826: 109. Type species by monotypy, Ariadna insidiatrix Audouin, 1826.— World Spider Catalog (2018).
Pylarus Hentz, 1842: 225. Type species, Pylarus bicolor Hentz, 1842.— Beatty (1970: 458).— Emerton (1875: 20; 1876: 131, Syn.).
Macedonia Hogg, 1900: 85. Type species by monotypy, Macedonia burchelli Hogg, 1900.— Simon (1908: 380, Syn.).— Rainbow (1911: 136).
Segestriella Purcell, 1904: 165. Type species by monotypy, Segestriella gryllotalpa Purcell, 1904.— Beatty (1970: 454, Syn.).
Diagnosis. The American Ariadna differ from the other Segestriidae genera by the following characters: from Segestria and Gippsicola by the labium narrowed in its distal portion (Fig. 3E), labrum well-developed, longer than the labium, and without dorsal median setae (Figs 3F, 18B, 20B), presence of a lateral basal transverse ridge in the chelicerae (Fig. 3C; Ramírez 2014: 40, fig. 18H) posterior eyes in a straight or slightly recurved line (Figs 3A‒B, 64C), absence of tenent setae on the legs (Figs 7, 12C‒E, H‒I), tarsus of the female palps with a group of five or more macrosetae (Fig. 4F), and posterior receptaculum with tubular invaginations (Figs 10E‒G, 11D); from Citharoceps by the absence of the stridulatory apparatus (Giroti and Brescovit 2015: 4, figs 1A‒C, 2A‒B), labiumsternum junction larger than the length of the endite-sternum junction (Figs 3E, 18B), and females with an interpulmonary fold lacking a conspicuous median flap (Fig. 9A‒B).
Description. Coloration: Carapace color ranging from light orange to dark reddish tones (Figs 14F, 56A); eyes bounded by dark outlines (Fig. 54A); legs and palps colors ranging from light yellow to dark reddish tones (Figs 17A‒B, 65A‒B); abdomen color ranging from light gray with a conspicuous dark dorsal pattern (Fig. 18A‒B), to dark grey (Fig. 64A‒B). Total length: 2.8‒20.25; carapace 1.38‒5.6 long, 1.02‒3.8 wide. Carapace: oblong, cephalic region narrower than thoracic region, posterior border straight or slightly concave (Figs 14A 31E); sparsely distributed setae usually concentrated in its edge and in the cephalic region; thoracic fovea smooth/ inconspicuous with only a shallow depression for muscular insertion (Fig. 3A‒B). Eyes: six indirect eyes, anterior median eyes absent, lateral eyes arising from a single tubercle (Fig. 3A‒B). Chelicerae: conical, frontal surface flattened, wider basally in lateral view, usually projected forwardly in males; lateral basal transverse ridge prominent (Fig. 3C); frontal basal longitudinal band of ridges and/or tubercles present, without insterstitial setae (Fig. 3C); setae scattered distally on the paturon frontal and lateral region (Figs 3C, 36G); cheliceral teeth composed by three promarginal and one retromarginal, all conical, and with ridged cuticle (Fig. 3D, left inset); cheliceral gland with scattered pores (Fig. 3D, right inset); posterior distal region with a depression, where the endites distal end fits (Fig. 3D); fangs short, almost two times the diameter of the distal part of the paturon, shaft with an internal serrula (Fig. 3D). Mouthparts: labrum well-developed, longer than the labium, without dorsal median setae (Figs 3F, 18B, 19B); endites spatulate, obliquely depressed, narrowed medianly (Ramírez 2014: 60), and rounded proximally (Fig. 3E‒F), hyaline distal prolateral end bearing a setae tuft (Figs 3E‒F, 12G); setae tuft composed by cylindrical setae with one row of conical barbs (Fig. 3F, inset); serrula with a single row of teeth (Fig. 3F); labium longer than wider, narrowed in its distal portion, 2/3 of the length of the endite, separated from the sternum by a partially membranous suture (Figs 3E, 38B). Digestive system: labial plate with lateral transverse walls, slightly narrowed distally, labrum duct straight, connected to the esophagus through a short pharynx which leads to the sucking stomach (Fig. 11A‒B). Sternum: longer than wider, anterior region truncated, straight or slightly concave, not fused with the carapace or the pedicel ventral sclerite (Fig. 36H). Male palp: tibiae basally swollen, longer than the cymbium (Figs 4A, 17B), and with one or two dorsal trichobothria; cymbium forming a distal notch with the prolateral portion slightly longer than the retrolateral one, forming a distal notch (Figs 4B, 51B), sometimes bearing a dorsal chemosensory setae patch (Figs 15A, 48A); bulb rounded or subrectangular, abruptly narrowed forming a mid-portion between the bulb and the embolus, the latter curved forwards (Figs 4A, 21A‒B); spermatic duct with an internal porous stripe with one convolution inside the bulb (Figs 4D‒E, 17A‒B; following Cooke 1966: 37; Cooke 1970: 143, 145), becoming narrow and hyaline between the mid-portion and embolus (Fig. 5A, following Lipke et al. 2014); embolus tubular (Fig. 4A‒C). Female palp: short and robust, with one articulated smooth claw at the tip, diaxially orientated (Fig. 4G), and scattered macrosetae on the prolateral region of the tarsi and tibiae (sometimes patellae) (Fig. 4F); tarsi surrounded almost entirely by tactile setae (interstitial chemosensory setae is also found), the ventral ones thickened, strongly serrated, and gradually decreasing in size in distal direction (Fig. 4F‒G); tibia with one dorsal trichobothria. Legs: robust, prograde, with the third pair directed forward (Figs 7A‒C, 18F‒I), usually with pairs I‒II with more setae and macrosetae than pairs III‒IV; metatarsi and tarsi IV with a ventral brush of thickened and serrated setae and metatarsi IV with a distal ventro-retrolateral preening comb of macrosetae (Figs 5B, 7E‒F); leg formula I-II-IV-III or II-I-IV-III; three tarsal claws, superior ones pectinated, and inferior one with only a small tooth (Figs 6E, 7C‒D); tarsal organ exposed with edges, and usually two rimmed receptors (Fig. 6E‒F; Platnick et al. 2012: figs 36‒45); trichobothria on the dorsal subdistal region of metatarsi I‒IV, dorsal subproximal region of tibia I‒IV; trichobothrial bases with a transverse ridge, and without a well-delimitation between proximal and distal plate (Fig. 4B, inset); tenent setae absent in all legs; males with a tarsal brush of putative chemosensory setae located in the ventral region (Fig. 5B, following Foelix et al. 2010, figs 1‒2; Ramírez 2014: 125); male metatarsi I usually bearing projections, apophyses or modified macrosetae (Fig. 6A‒D); female tibiae and metatarsi without ventral and dorsal macrosetae, only ventro-prolateral, ventro-retrolateral, and sometimes prolateral and retrolateral (Fig. 7A‒C); female tarsi I‒II with ventro-prolateral lines of thickened tactile setae, interspersed with lines of chemosensory setae (Fig. 7D, G). Abdomen: longer than wide, uniformly hairy, coated with short setae, and scattered long setae among them (Fig. 16F‒G); book lung cover weakly sclerotized, and ventral anterior sigillae distinct, with slit sensillae (Fig. 22H); tracheal system dysderoidlike, with tracheoles spreading through the cephalothorax, including all the appendages, and the abdomen (Figs 9A, 11A‒C; Ramírez 2000: 153; Griswold et al. 2005: 39). Spinnerets: ALS with three segments, the basal segment crossed by a diagonal membranous stripe (Fig. 8A), one MAP spigot with a prolateral field of about 15 strain sensillae, divided in two rounded and one canoe-shaped area (Fig. 8D‒E); PMS with one mAP and one AC spigot (Fig. 8C); PLS usually with 3‒4 AC (Fig. 8B); colulus distinct and pilose (Fig. 8F). Female genitalia: external plate distinct and sclerotized (Fig. 22H); internal genitalia composed by anterior receptaculum, uterus externus, interpulmonary fold, and posterior receptaculum (Figs 9, 10, 11C‒D, 33C); anterior receptaculum usually billobulated, with a dorsal and a ventral lobe, both being dead-end structures, and a glandular ducts plate that fills the median space between the two lobes (Figs 9B, 10A‒B, 17C‒D); glandular ducts plate heavily sclerotized (i.e. anterior receptaculum most sclerotized region), composed by cuticular ducts with expanded bases that allows glandular cells to discharge secretion in the lumen of the anterior receptaculum through pores in its cuticle (Figs 9B‒D, 10A‒B, 35C‒D); interpulmonary fold with dorsal smooth curvature, with a median membranous crack (absent in A. araucana and A. lalen n. sp.) (Fig. 9A‒B); posterior receptaculum composed by a membranous sac that originates from the posterior wall of the bursa copulatrix, with pores connected with tubular invaginations that goes towards the lumen (Figs 9A‒C, 10C‒G, 11C‒D).
description: Published as part of Giroti, André Marsola & Brescovit, Antonio Domingos, 2018, The taxonomy of the American Ariadna Audouin (Araneae: Synspermiata: Segestriidae), pp. 1-114 in Zootaxa 4400 (1) on pages 12-13, DOI: 10.11646/zootaxa.4400.1.1, http://zenodo.org/record/1207641