Bioacoustics of Nerudia ola

Description Male ( holotype ). Measurements: Total body length 1.55, carapace width 0.66. Distance PME–PME 70 µm; diameter PME 65 µm; distance PME–ALE 30 µm; distance AME–AME 20 µm; diameter AME 40 µm. Leg 1: 5.64 (1.48 + 0.25 + 1.45 + 1.78 + 0.68), tibia 2: 1.18, tibia 3: 1.03, tibia 4: 1.53; tibia 1 L/d: 22. Colour (in ethanol): Prosoma and legs mostly pale ochre-yellow; carapace with light brown Y-mark behind ocular area; sternum whitish; legs without dark rings; abdomen monochromous pale grey. Body: Habitus as in Figure 1G . Ocular area barely raised. Carapace with indistinct thoracic groove. Clypeus unmodified (only rim slightly more sclerotized than in female). Sternum wider than long (0.46/0.38), with pair of distinct anterior processes near coxae 1. Abdomen globular. Chelicerae: As in Figure 27G, H ; with distinctive pair of long frontal apophyses, tips slightly bent downwards, obtuse in frontal view, with some ventral hairs directed downwards ( Fig. 29F ); distance between tips of apophyses: 280 µm; stridulatory files on distinct lateral protrusions ( Fig. 29C ). Palps: In general, similar to N. colina (cf. Fig. 4 ) but femur slightly slenderer (length/width 2.27) and tibia slightly thicker (length/width 0.92); procursus simple, in lateral view slightly directed towards dorsal, with bifid tip consisting of slender dorsal process and wider ventral membranous process ( Fig. 27A–C ); genital bulb similar to N. colina , with slender ventral apophysis curved towards ventral ( Fig. 27D–F ). Legs: Without spines and curved hairs; with vertical hairs in higher than usual density on proximal half of tibia 1 only, in two dorsal rows ( Fig. 30A ); retrolateral trichobothrium of tibia 1 at 58%; prolateral trichobothrium absent on tibia 1; tarsus 1 with six to seven pseudosegments, distally distinct. Variation (male): Tibia 1 in 36 males (including holotype ): 1.04–1.60 (mean 1.33). The distance between the tips of the cheliceral apophyses varies considerably (235–340 µm), but also within localities (e.g. Nacimientos: 240–310 µm). In northern specimens (from La Rioja and Catamarca ), the cheliceral apophyses are slightly straighter and longer. This difference is minimal and some males appear intermediate. In specimens from Chumbicha , the procursus is slightly shorter. Abdomen variably dark. COI data indicate a deep split between northern and southern specimens, and a phylogenetic analysis of the molecular data (Supporting Information, Fig. S2 ) even questions the monophyly of the northern + southern clade. However , deep splits also occur among southern specimens and among northern specimens ( Fig. 2 ). As a result, a preliminary ASAP analysis (Supporting Information, Figs S3 , S 4 ) favours the existence of up to seven ‘species’ (lowest scores of 2.0 and 3.0). What is here interpreted as one species may thus in fact be several more or less cryptic species . Female: In general, similar to male but sternum without pair of anterior humps and tibia 1 with usual low number of short vertical hairs. Tibia 1 in 57 females : 0.97–1.55 (mean 1.25). Epigynum ( Figs 28A , 30F ) anterior plate weakly protruding, without posterior indentation; posterior plate large, simple. Internal genitalia ( Figs 27I , 28B–D ) simple, with barely visible transparent receptacle. No difference could be seen between northern and southern specimens.