Nerudia Huber 2000
Creators: name: Huber, Bernhard A.
name: Meng, Guanliang
name: Král, Jiří
name: Ávila Herrera, Ivalú M.
name: Izquierdo, Matias A.
name: Carvalho, Leonardo S.
Publisher: name: Zenodo
Year: 2023
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Arachnida
Araneae
Pholcidae
Nerudia

description: NERUDIA HUBER, 2000
Nerudia Huber, 2000: 87. Type species: Nerudia atacama Huber, 2000.
Diagnosis: Small (total body length 1.4–1.9) eighteyed pholcids with relatively long legs (compared to most other Ninetinae; leg 1 usually> 3 × total body length; only shorter in the new species N. centaura), with simple procursus (without dorsal flap, not strongly elongated), paired male cheliceral modifications (strong hairs or pair of apophyses), with stridulatory files on male chelicerae, with simple main (anterior) epigynal plate and large posterior epigynal plate, without or with simple (i.e. not tube-like) median receptacle-like structure in female internal genitalia.
Description
Male. Measurements: Total body length 1.4–1.9, carapace width 0.6–0.8. Legs relatively long (compared to other Ninetinae), tibia 1 usually ~1.1–2.0 (longer in the new species N. rocio, single male: 2.5); tibia 1 L/d 14–31; metatarsus 1 length ~1.0–1.2 × tibia 1 length; tibia 2 always shorter than tibia 4 (tibia 2/tibia 4: 0.8–0.9).
Colour: Live specimens pale ochre-grey to light brown (Fig. 1); carapace often with darker median mark; abdomen colour variable, often darker than prosoma, only in N. centaura distinctively lighter than prosoma (Fig. 1C), without or with indistinct marks; legs without dark or light bands. Colour in ethanol similar but paler.
Body: Ocular area barely raised, eight eyes, AME relatively large (diameter: 35–50 µm, i.e. 60–85% of PME diameter). Carapace without or with indistinct thoracic groove (cf. Figs 7B, 11A, 29A). Clypeus usually barely modified, rim slightly more sclerotized than in female, in N. nono also more bulging than in female, in some species with pair of shallow indentations for genital bulbs at rest (Figs 7A, 11B). Sternum wider than long, usually with pair of variably distinct anterior processes near leg coxae 1, processes apparently without pores (Fig. 29G); sternum processes absent in N. centaura. Abdomen globular; four epiandrous spigots arranged in two pairs (Figs 11F, 29H); ALS with seven spigots each (Fig. 30G): one strongly widened spigot, one long pointed spigot and five cylindrical spigots (one of which is unusually large); PMS with two short, pointed spigots (Fig. 30G); PLS without spigots (cf. Fig. 12D).
Chelicerae: Usually with pair of simple frontal apophyses (e.g. Fig. 5G, H; absent in N. trigo), tip often flat, i.e. wide in frontal view, pointed in lateral view (Fig. 11C, D); often with patches or brushes of stronger hairs; with stridulatory files on variably distinct lateral protrusions (Figs 11B, C, 29C).
Palps: Coxa unmodified; trochanter with indistinct ventral projection; femur cylindrical, slightly widened distally, proximally without or with low retrolateral hump, with prolateral stridulatory pick (modified hair; Fig. 29E); patella short; tibia globular, with two trichobothria; palpal tarsal organ raised, capsulate (Figs 7E, 11E, 30C), with small opening (diameter of opening ~1.6–1.9 µm); procursus simple, without dorsal flap, not strongly elongated, straight or bent towards dorsal, tip with complex cuticular microstructure (Fig. 29B); genital bulb with simple ventral apophysis and dorsal embolus (e.g. Fig. 5F).
Legs: Without spines and curved hairs; usually with short vertical hairs in higher density on tibia 1 or tibiae 1 and 2 (Figs 8A, B, 30A; length of hairs ~20 µm). Trichobothria in usual arrangement: three on each tibia (except tibia 1: prolateral trichobothrium absent), one on each metatarsus, slightly feathered (Fig. 30B); length of dorsal trichobothrium on tibia 1: ~80 µm; retrolateral trichobothrium of tibia 1 in distal position (at 58–70% of tibia length). Metatarsi and tarsi with dorsal rows of tiny pores with cuticular rim (diameter of opening ~0.6 µm; cf. Fig. 18C, D). Tarsus 1 with six to eight pseudosegments, distally distinct, proximally usually indistinct; tarsus 4 distally with one comb-hair on prolateral side (Fig. 12F); leg tarsal organs small, capsulate (Fig. 30E), with small opening (diameter of opening ~ 1.2–1.6 µm); three claws (Figs 12E, 18G).
Female: In general (size, colour, body shape), similar to male but chelicerae without stridulatory files (Figs 7D, 24F, 29D), sternum without pair of anterior humps, palpal tarsal organ only weakly raised (Figs 12A, B, 24B), and leg tibiae with usual low number of short vertical hairs; legs either slightly shorter than in males or of same length (only in the new species N. ola with reasonable sample size: male/female tibia 1 length: 1.08). Spinnerets, leg pores, leg tarsal organs and comb-hairs as in male (Figs 7F, 8D–F, 18B, H, 24H, 30E, H). Main (anterior) epigynal plate rectangular to trapezoidal or semi-circular, weakly protruding, posteriorly straight or with variably distinct median indentation (e.g. Figs 17A, 32A); posterior plate simple, short but wide, usually wider than anterior plate. Internal genitalia simple, sometimes with distinct median receptacle-like structure (e.g. Figs 6B, 10B), apparently without or with indistinct pair of pore plates (arrows in Figs 10B, 14B, 23B).
Relationships: The molecular analysis of Eberle et al. (2018) included only a single species of Nerudia (‘ N. Mich20 ’ = N. ola), which was placed (with moderate support) as sister of the geographically close Gertschiola macrostyla (Mello-Leitão, 1941). Both genera together were placed in a clade with further South American and Old World Ninetinae. The present paper is not primarily focused on phylogeny and our sampling does not include the type species N. atacama, but our COI and karyotype data support the sister-group relationship between Nerudia and Gertschiola (see Fig. 2; Supporting Information, Figs S1, S 2; and section on karyology). Preliminary analyses of Ninetinae relationships based on hybrid enrichment data (G. Meng et al., unpublished data) also support this sister-group relationship. Our new SEM data also confirm the position of Nerudia among Ninetinae (in particular the small opening of the tarsal organs).
In addition, the COI data suggest the existence of three species groups within Nerudia that we consider useful as working hypotheses: (1) the ola group, including the new species N. guirnalda, N. nono, N. ola and N. trigo; (2) the centaura group, including the new species N. centaura, N. rocio and the undescribed N. ‘Arg23a’; and (3) the poma group, including the new species N. hoguera, N. poma and the undescribed N. ‘Arg163’. One new species, N. colina, appears isolated. The three groups appear neither supported nor contradicted by morphology. The type species N. atacama and the new N. flecha cannot be assigned with confidence to any of these groups (no fresh material suitable for sequencing is available of these two species).
Distribution: Nerudia iswidespreadintheArgentinean and Chilean Andes, ranging at least from 24°S to 31°S, and in the east up to the Córdoba mountain ranges in central Argentina (Fig. 3). See biogeographic analysis for further details and distribution modelling.
Natural history: Most species were found in relatively arid environments (Fig. 45A–F), and some seem to tolerate extremely dry and cold conditions (see Natural history section of N. centaura and biogeographical analysis for further details). In a few cases, Nerudia has been found in relatively humid forested areas, e.g. N. guirnalda at El Rodeo or N. ola and N. poma at Chumbicha (both: Argentina, Catamarca). Most specimens were found by turning stones and rocks. Two species (N. poma and N. trigo) were also found on the ceilings of small cave-like shelters composed of large rocks and boulders. Nerudia nono was collected by turning stones of a loosely built wall situated in the sun (Fig. 45F). When disturbed, the spiders either remained more or less motionless or they ran rapidly a few centimetres over the rock surface; they seemed reluctant to drop to the ground. Webs were not seen in the field, but at least N. nono was observed to build flimsy webs in small containers in the laboratory. In most visited localities, only one species of Nerudia was found; in a few cases, two or even three species were found at a single locality, apparently in identical microhabitats. Other pholcid spiders sharing the microhabitats of Nerudia were Gertschiola macrostyla and Guaranita Huber, 2000 spp. (Ninetinae), Chibchea Huber, 2000 spp. and other small undescribed representatives of Modisiminae, and an undescribed species of Metagonia Simon, 1893 (Pholcinae). Egg sacs were slightly flattened (but never reduced to a single layer of eggs as in Guaranita) and consisted of about eight to 18 eggs.
Composition: The genus now includes 11 described species, ten of which are newly described below.
description: Published as part of Huber, Bernhard A., Meng, Guanliang, Král, Jiří, Ávila Herrera, Ivalú M., Izquierdo, Matias A. & Carvalho, Leonardo S., 2023, High and dry: integrative taxonomy of the Andean spider genus Nerudia (Araneae: Pholcidae), pp. 534-591 in Zoological Journal of the Linnean Society 198 on pages 540-543, DOI: 10.1093/zoolinnean/zlac100, http://zenodo.org/record/7981762