Maratus inaquosus sp. nov.

(Figs 15 A–F, 16A–C, 17A–C, 18A–F, 19A–D, 20)

Material examined. MALE HOLOTYPE (MV-K13592) from Australia, Victoria, Little Desert National Park, 36°33’44.4” S 141°59’22.1” E. 28 Oct 2019 . PARATYPES: 1 female (MV-K13593), same collection data as holotype .

Etymology. The specific name ( inaquosus, Latin, m, adjective, English translation: arid, dry, lacking water) refers to dry habitat where this species is typically found in.

Diagnosis. This species belongs to the Maratus anomalus group (Otto & Hill, 2019a), with respect to the structure of the embolus of the male palp, bearing a large outer ring terminating in a bifurcated apex, and a smaller inner ring with a pointed apex. Males of M. inaquosus most closely resemble Maratus anomalus (Karsch, 1878) and Maratus vultus Otto & Hill, 2016, but can be distinguished from these species by their unique light golden and blue dorsal opisthosomal markings, and by the two distinctive stripes present on each lateral slope of the carapace. Additionally, the bicoloured pedipalps of M. anomalus bear longer white setae on the inner dorsolateral surface, whereas in M. inaquosus longer white hairs are instead present on the outer dorsolateral surface of each pedipalp.

The females of M. inaquosus are similar to other members of the M. anomalus group, and identification may not be possible without association with a male. The structures of the external male and female genitalia of M. inaquosus is of little use in distinguishing them from other members of the M. anomalus group.

Description. Male. Cuticular surface of carapace dark brown, almost black. Ocular quadrangle region thickly covered with grey scales. Red tract of scales extends from anterolateral edge of each AME to each PLE (Fig. 15 A– F). Broad lateral tracts of white setae extend from each posterolateral edge of ocular quadrangle region to rear slope of carapace (Fig. 15A, C–F). Marginal band of setae on carapace absent. Two distinctive stripes present on each lateral slope of carapace, extending upwards from rim of carapace (Fig. 15C, F, Fig. 16B). Anterolateral surface of carapace with less distinct tract of white setae extending from rim of carapace to ALE (Fig. 15C, F, Fig. 16B).

PME closer to PLE than to ALE. AME ringed with short, red-orange scales on outer dorsolateral margin and grey scales on inner dorsolateral margin. Ventral margin of AME ringed with grey scales. Dorsal margin of ALE ringed with short, red-orange scales and ventral margin with grey scales. Long, grey setae project downwards from below AME over clypeus forming triangular shape (Fig. 15B). Cuticular surface of clypeus dark brown to black and covered with short, grey setae. Chelicerae dark brown and glabrous. Coxae pale, labium and endites dark brown and glabrous. Sternum dark brown with light covering of fine, grey setae (Fig. 16C).

Dorsal opisthosoma with dense covering of iridescent blue scales interspersed with light-golden scales. Pair of distinctive dark spots of scales bordered by red-orange scales present slightly below midpoint of dorsal opisthosoma. Anterior margin of dorsal opisthosoma covered with white scales. Two strongly diverging tracts of golden scales extend from anterior margin of opisthosoma towards lateral edges ~1/3 the length down opisthosoma. Thin band of orange scales present at posterior margin of opisthosoma. Opisthosoma rounded and lacking lateral opisthosomal flaps (Fig. 15A, C-F). Colular tuft of white setae situated above black spinnerets. Ventral opisthosoma dark brown and scattered with short, creamy-coloured setae (Fig. 16C).

Legs I and II subequal in length, legs III and IV longer, legs III by far longest. Each leg dark brown with light covering of long, off-white setae. Distinct longitudinal black stripe running along femora, patellae, and tibiae of legs III. Tarsi of legs III covered with white setae (Fig. 15 A–F). Pedipalp bicoloured; band of off-white setae present on dorsal surface of pedipalp, with longer white hairs extending downward from outer dorsal lateral edge, contrasting dark ventral bulb covered with dark grey hairs (Fig. 15B). Relatively large male palpal bulb with retrolateral sperm duct loop, large retrobasal tegular lobe, finger-like retrolateral tibial apophysis, embolic disc with anticlockwise coiled embolus. Embolus with prominent outer ring terminating in bifurcated apex, and short inner ring with pointed apex (Fig. 17A, C). Heavily sclerotized cuticle on tegulum prolaterally below emolic disc (Fig. 17 A–C).

Female. Ocular quadrangle region with thick cover of red-brown to off-white setae. Broad tract of off-white setae extends from behind each PLE to rear margin carapace, surface between dark brown, almost black. Lateral slopes of carapace light brown with light covering of white setae (Fig. 18 A–F). Carapace lacking median thoracic tract and marginal band.

Each anterior eye ringed with off-white and red-brown scales or setae. Long white setae project downwards from below AME forming triangular shape. Clypeus covered with short, white setae (Fig. 18B, F). Chelicerae dark brown and glabrous. Coxae pale, endites and labium dark brown, translucent and mostly glabrous. Sternum dark brown with light covering of fine, white setae (Fig. 19C).

Dorsal opisthosoma dark brown with incomplete cover of off-white and light brown setae. Lateral opisthosoma with thicker covering of off-white setae (Fig. 18 A–F). Colular tuft of white setae situated above spinnerets. Ventral opisthosoma light brown with irregular light spots (Fig. 19C).

Legs I and II subequal in length, legs III and IV longer, legs III longest. Each leg with incomplete cover of offwhite and brown setae, integument below light brown and translucent. Darker ring of setae at each leg joint (Fig. 18 A–F). Pedipalps light brown and translucent with incomplete cover of white setae. Epigynum with pair of large ovate fossae separated by septum. Ovate posterior spermatheca behind each fossa. Sclerotized ducts present anterior to each spermatheca (Fig. 19D).

Variation. The degree of golden scales which cover the dorsal opisthosoma of the males varies as compared to specimens shown in images of this species (‘ Maratus cf. anomalus’, Otto & Hill, 2016) taken by Jürgen Otto.

Courtship display. The opisthosoma of the male is raised and flattened and held in an erect position. One of or both of legs III are raised and elevated in a partially flexed position and slowly moved from side to side, and the male steps from side to side as the female approaches (Fig. 20).

Dimensions. Male. Total length: 3.55. Carapace length 1.97. Opisthosoma length 1.58. Leg I length: 2.77. Leg II length: 2.79. Leg III length: 3.89. Leg IV length: 3.53.

Dimensions. Female. Total length: 5.42. Carapace length 2.44. Opisthosoma length 2.98. Leg I length: 2.51. Leg II length: 2.53. Leg III length: 4.23. Leg IV length: 3.78.

Distribution. Known from the type locality in Little Desert National Park, Victoria (Fig. 1). Otto & Hill (2016) also recorded this species as ‘ Maratus cf. anomalus’ in the Warby-Ovens NP, Victoria. Type specimens found in the dry grasses shown in Fig. 21A, B.