Ariadna tigrina sp. nov.

Figs 37a–h, 38a–c, 39a–h, 40a–b, 41

http://zoobank.org/NomenclaturalActs/2f7f9202-8f9a-4b77-b1c8-9494748f5b02

Type material. Holotype ♂. AUSTRALIA: Tasmania: Flat Rock, 42.99°S; 147.95°E

2010, coll. R. Raven, Bush Blitz expedition (TMAG J5354).

Paratype ♀: same as holotype (TMAG J5355) .

Other material examined. 2 ♂, 5 ♀, 11 juveniles, same data as holotype, (TMAG J4139); 4 ♂, Risdon, 42.79°S, 147.32°E, 10 September 1963, J.L. & V. V . Hickman (AM KS.29169) ; 2 ♂, 2 ♀, East Risdon, 42.79°S, 147.35°E, September 1975, V. V . Hickman (AM KS.29171) ; 1 ♀, East Risdon, 42.79°S, 147.35°E, 28 May 1936, V. V . Hickman, 2 ♂ (AM KS.29173); 3 ♂, Risdon, 42.79°S, 147.32°E, 19 May 1937, V. V . Hickman (AM KS.29205) ; 1 ♂, Risdon, 42.79°S, 147.32°E, 03 July 1943, V. V . Hickman (AM KS.31091) ; 2 ♂, 1 ♀, Fingal, 41.64°S, 147.97°E, 24 May 1928, V. V . Hickman (AM KS.29202) .

Etymology. The specific epithet is an adjective meaning ‘tigrine, striped’ and refers to the transverse pale and dark striations on this species’ abdomen.

Diagnosis. Ariadna tigrina sp. nov. is closest to A. abbreviata sp. nov., A. burchelli, A. clavata and A. fragilis sp. nov.,. It can be distinguished from A. abbreviata sp. nov. by lacking the row of three blunt macrosetae on metatarsus I of males (Fig. 37f, g cf. Fig. 1f, g). It can be differentiated from Ariadna burchelli by the presence of macrosetae on the tibia of the female (Fig. 39f–h cf. plate 8, fig. 4 Hogg 1900). The species is distinguished from A. clavata by the number of macrosetae in the preening comb of leg IV, being seven macrosetae in A. tigrina sp. nov. and five in A. clavata (Figs 37e, 39e cf. figs 1e, 2h Marsh et al. 2018); by the number and pattern of macrosetae on the tibia and metatarsus of leg I of males and females (Figs 37f–h, 39f–h cf. figs 1a, 2a, b, d–f Marsh et al. 2018) and by molecular sequencing, with an interspecies divergence of 15.3% (Table 2). Ariadna tigrina sp. nov., is differentiated from A. fragilis sp. nov. by the pattern of macrosetae on leg I of the tibia and metatarsus of males (Fig. 37f–h cf. Fig. 20f–h) and by the curvature of the embolus, which is more strongly hooked in A. tigrina sp. nov. (Fig. 38a–c cf. Fig. 21a–c). Ariadna thylacinus sp. nov. is from the same type locality as A. tigrina sp. nov., the two species can be differentiated by the shape of the pedipalp bulb, which is pyramidal in A. tigrina sp. nov., but rounded oblong in A. thylacinus sp. nov., by the shape of the embolus, which is fine, smoothly curved and hooked apically in A. tigrina sp. nov., but is sinuous apically in A. thylacinus sp. nov. and by the pedipalp tibia, which is inflated in A. thylacinus sp. nov. (Fig. 38a–c cf. Fig. 35a–c).

Description. ♂ (based on holotype; TMAG J5354). Total length 4.8.

Colour in ethanol: Carapace red-brown, with scattered sparse brown setae, border a darker brown, caput area bordered by darker red-brown striations; sternum yellow brown, with regular slightly darker inter-coxae patches, scattered long dark setae, maxillae and chelicerae orange brown labium brown; abdomen dorsally with about 9 dark grey, clearly defined chevrons, interspersed with pale cream, ventrally pale cream, with mottled and patchy dark grey median band. Legs yellow brown, with sparse dark setae (Fig. 37a–h).

Cephalothorax: 2.3 long, 1.7 wide, 1.4 high. Carapace rounded oval, narrowing anteriorly forming a neck, edges gently undulating and rebordered, fovea a shallow indentation (Fig. 37a); from lateral view carapace rising gently anteriorly, highest just posterior to eyes (Fig. 37c). Labium narrowed anteriorly, about ¾ length of maxillae; chelicerae with basal transverse ridge, retromargin with single tooth, promargin with three teeth; sternum oval, with large, defined precoxal triangles, larger posteriorly and with smaller, broadly triangular intercoxal extensions (Fig. 37b). Posterior eye row slightly recurved, eye group occupying 0.6 of carapace width (Fig. 37d).

Abdomen: 2.5 long. Covering of fine brown setae (Fig. 37a).

Legs: Leg length ratio I>IV>II>III. Leg I femur 1.8, patella 0.7, tibia 1.5, metatarsus 1.5, tarsus 0.7; Leg II femur 1.2, patella 0.7, tibia 1.0, metatarsus 1.2, tarsus 0.6; Leg III femur 1.3, patella 0.5, tibia 0.9, metatarsus 1.0, tarsus 0.6; Leg IV femur 1.4, patella 0.7, tibia 1.3, metatarsus 1.2, tarsus 1.5. Femur I slightly bowed in dorsal view. Tarsi I slightly bowed ventrally in lateral view, broader at apex than at base; tarsi II – IV similar, but less bowed or broad. Leg I femur d1-1/0-1/0, dp2ap; tibia p1-1-1, pv1-1-1-1-1ap, v1-1-1/0, rv1-1/0-1/0-1ap, r1-1-1-1; metatarsus p1, pv1-1-1-1ap, rv1-1-1ap, r1. Leg II femur d1, dp1ap; tibia p1-1-1, pv1-1-1ap, rv1-1-1ap, r1-1-1; metatarsu s p1, pv1-1-1-1ap, rv1-1-1ap, r1. Leg IV femur d1-1-1-1/0, dp1ap; tibia p1-1, v1-1-1ap; metatarsus v1, rv1-1-1ap, r1. Retrolateral distal preening comb with 7 spines, even in length (Fig. 37e). STC I, II with 9 teeth, ITC with long, thin tooth. Tarsi with sparse distal ventral scopulose setae.

Pedipalp: Pedipalp tibia about twice the length of the cymbium, cymbium with anterior prolateral extension, scopulose setae anteriorly; bulb rounded pyramidal in lateral view, embolus long, thin and hooked apically (Fig. 38a–c).

Description. ♀ (based on paratype; TMAG J5355). Total length 6.9.

Colour in ethanol: Carapace reddish-brown, with raised lighter area at and anterior to fovea and with fine darker line around edges, sparse scattered setae, denser towards around eye group, sternum orange brown, paler medially, with regular slightly darker inter-coxae patches, with moderately long black setae, denser towards edges; labium dark red brown, paler apically, maxillae orange brown, paler apically, chelicerae orange-brown with dense, long, black setae; abdomen dorsally dark with eight dark grey, clearly defined chevrons, broader and connecting at midpoints, extending laterally and ventrally, interspersed with pale cream; ventrally cream with ill-defined, linear dark grey line centrally. Legs golden brown, legs I, II with dense setae, III, IV less dense (Fig. 39a–h).

Cephalothorax: 2.8 long, 1.8 wide, Carapace oval, with broad, square ‘neck’ anteriorly, anterior edge convex, laterally edges gently undulating (Fig. 39a); from lateral view carapace raised to fovea and then levelled until it lowers just posterior to eyes (Fig. 39c). Labium narrowed anteriorly, about ¾ length of maxillae; chelicerae broad, robust with basal transverse ridge, retromargin with single tooth, promargin with three teeth; sternum elongated oval with large, defined precoxal triangles, larger posteriorly and with small, rounded intercoxal extensions (Fig. 39b). Posterior eye row slightly recurved, eyes occupying about 0.5 of carapace width (Fig. 39d).

Abdomen: 4.1 long; with short, dense setae (Fig. 39a).

Legs: Leg length ratio I>IV>II>III. Leg I femur 1.9, patella 0.9, tibia 1.4, metatarsus 1.2, tarsus 0.6; Leg II femur 1.8, patella 0.6, tibia 1.5, metatarsus 1.1, tarsus 0.5; Leg III femur 1.3, patella 0.6, tibia 1.1, metatarsus 0.8, tarsus 0.5; Leg IV femur 1.8, patella 0.8, tibia 1.4, metatarsus 1.2, tarsus 0.6. Femur I bowed in dorsal view. Macrosetae: Leg I femur: dp2ap; tibia p1, pv1-1-1-1ap, rv1-1-1ap; metatarsus v2-2-2-2-1/2. Leg II femur dp1ap; tibia p1, pv1ap, rv1-1-1ap; metatarsus v2-2-2-2. Leg IV tibia v1-1, pv1ap; metatarsus v1, v1-1-1ap. Retrolateral distal preening comb with 7 spines (Fig. 39e). STC lef I with 9 teeth, ITC with small tooth. Tarsi with distal ventral setae.

Pedipalp: dense clusters of macrosetae prolaterally on tarsus and tibia. Scopulose setae on tarsus.

Genitalia: Anterior receptaculum sinuous in ventral view, bilobed (Fig. 40a–b).

Variation. Macrosetae of tibia and metatarsus I showed little variation between specimens examined for both males and females. Specimens showed some variation in colour, ranging from darker red-brown to lighter goldenbrown, in darker specimens the transverse abdominal markings were less distinct, but still decipherable. Specimens showed little variation in size.

Distribution. Known from eastern Tasmania (Fig. 41).

DNA barcode. A 654 base-pair (bp) fragment of the mitochondrial (mt) DNA cytochrome c oxidase I (COI) gene (DNA barcode) was sequenced for specimen TMAG J4139 (see other material information above) and is deposited in BOLD (Process ID OZBOL2585-21) and GenBank (accession number ####). The base composition of the DNA barcode sequence is 22.17% A, 40.52% T, 13.61% C and 23.70% G (G + C = 37.31%).