Nerudia, HUBER, 2000

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), Zoological Journal of the Linnean Society 198, pp. 534-591 : 540-543

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.

Figures

Figure 1. Nerudia, live specimens from Argentina. A, N. colina sp. nov., female from Jujuy, between San Salvador and Purmamarca (type locality). B, N. poma sp. nov., male from Salta, NW Campo Quijano (type locality). C, D, N. centaura sp. nov., male and female from Catamarca, E Paso de San Francisco (type locality). E, N. trigo sp. nov., female from Salta, SW Alemania. F, N. guirnalda sp. nov., male from Catamarca, El Rodeo (type locality). G, N. ola sp. nov., male from San Juan, San Agustin de Valle Fertil (type locality). H, N. nono sp. nov., male from Cordoba, E Nono (type locality).

Figure 2. NJ COI tree of all sequenced Nerudia and Gertschiola specimens. Species groups on the right are working hypotheses. Photo: female of Nerudia colina sp. nov. For complete tree, and for tree resulting from analysis with IQ-TREE, see Supporting Information, Figures S1, S2.

Figure 3. Known distribution of Nerudia in South America (inset) and of individual species. Regions in Chile: AT, Atacama; COQ, Coquimbo. Provinces in Argentina: CA, Catamarca; COR, Córdoba; JU, Jujuy; LR, La Rioja; SA, Salta; SJ, San Juan.

Figure 5. Nerudia colina sp. nov.; paratype male and paratype female from Argentina, Jujuy, between San Salvador and Purmamarca (ZFMK Ar 23883).A–C, left male palpal tarsus and procursus, prolateral, dorsal, and retrolateral views (arrow points at distinctive subdistal sclerite). D–F, left male genital bulb, prolateral, dorsal, and retrolateral views. G, H, male chelicerae, frontal and lateral views. I, cleared female genitalia, dorsal view. Abbreviations: e, embolus; r, ‘receptacle’; va, ventral apophysis. Scale lines: 0.2 mm.

Figure 6. Nerudia colina sp. nov.; paratype female from Argentina, Jujuy, between San Salvador and Purmamarca (ZFMK Ar 23883). A, abdomen and epigynum, ventral view. B, median structures in internal genitalia. C, D, cleared genitalia, ventral and dorsal views. Scale lines: 0.2 mm (A, C, D), 0.1 mm (B).

Figure 7. Nerudia colina sp. nov.; male and female from Argentina, Jujuy, between San Salvador and Purmamarca (ZFMK Ar 23883 and ZFMK Arg178). A, male clypeus and chelicerae, frontal view (arrows point at indentations for genital bulb at rest). B, female prosoma, frontal view. C, left male chelicera, frontal view. D, female chelicerae and right palp, proximal segments, lateral view. E, male palpal tarsal organ. F, female tarsal organ on tarsus 1. Scale lines: 20 µm (A), 100 µm (B, D), 10 µm (C), 2 µm (E, F).

Figure 8. Nerudia colina sp. nov.; male and female from Argentina, Jujuy, between San Salvador and Purmamarca (ZFMK Ar 23883 and ZFMK Arg178). A, detail of male left tibia 1, prolateral view. B, hairs on male tibia 1. C, female palpal tibia, dorsal view. D, female left tarsus 4, prolateral view (arrow points at comb-hair). E, F, female ALS. Scale lines: 20 µm (A), 10 µm (B–F).

Figure 10. Nerudia poma sp. nov.; paratype female from Argentina, Salta, 15 km NW Campo Quijano (ZFMK Ar 23884). A, abdomen and epigynum, ventral view. B, median structures in internal genitalia. C, D, cleared genitalia, ventral and dorsal views. Scale lines: 0.2 mm (A, C, D), 0.1 mm (B).

Figure 11. Nerudia poma sp. nov.; male and female from Argentina, Salta, 15 km NW Campo Quijano (ZFMK Ar 23884, ZFMKArg184).A, female prosoma, frontal view.B, male clypeus and chelicerae, oblique distal view. C, D, right male chelicera, frontal views. E, male palpal tarsal organ. F, male gonopore. Scale lines: 100 µm (A), 20 µm (B), 10 µm (C, D, F), 2 µm (E).

Figure 12. Nerudia poma sp. nov.; male and female from Argentina, Salta, 15 km NW Campo Quijano (ZFMK Ar 23884, ZFMK Arg184). A, tip of female pedipalp, dorsal view; arrow points at tarsal organ. B, female palpal tarsal organ. C, left female ALS and PMS. D, left female PLS. E, male left tarsus 1 tip, prolateral view. F, male left tarsus 4 tip, prolateral view; arrow: comb-hair. Scale lines: 10 µm (A, C–F), 2 µm (B).

Figure 14. Nerudia hoguera sp. nov.; paratype female from Argentina, La Rioja, between Chilecito and Famatina (ZFMK Ar 23889).A, abdomen and epigynum, ventral view. B, median structures in internal genitalia (arrow points at possible pore plate). C, D, cleared genitalia, ventral and dorsal views. Scale lines: 0.2 mm (A, C, D), 0.1 mm (B).

Figure 17. Nerudia centaura sp. nov.; non-type female from Argentina, Catamarca, 20 km E Paso de San Francisco (ZFMK Ar 23891). A, abdomen and epigynum, ventral view. B, anterior median tube-like structure in internal genitalia (arrow). C, posterior median structures in internal genitalia; arrow: ‘receptacle’. D, E, cleared genitalia, ventral and dorsal views. Scale lines: 0.2 mm (A, D, E), 0.1 mm (B, C).

Figure 18. Nerudia centaura sp. nov.; female from Argentina, Catamarca, 20 km E Paso de San Francisco (ZFMK Arg216). A, epigynum, ventral view; arrow: possibly entry into tube-like internal structure. B, female ALS and PMS. C, putative glandular pores on female tarsus 3. D, glandular pore and slit sensillum(?) on female tarsus 4. E, tarsal organ on female tarsus 3. F, tip of female right tarsus 1, retrolateral view. G, tip of female right tarsus 3, retrolateral view. H, tip of female left tarsus 4, prolateral view; arrow: comb-hair. Scale lines: 100 µm (A), 10 µm (B, C, F–H), 2 µm (D, E).

Figure 23. Nerudia trigo sp. nov.; paratype female from Argentina, Salta, between Alemanía and Cafayate (ZFMK Ar 23894). A, abdomen and epigynum, ventral view. B, median structures in internal genitalia (arrow points at possible pore plate). C, D, cleared genitalia, ventral and dorsal views. Scale lines: 0.2 mm (A, C, D), 0.1 mm (B).

Figure 24. Nerudia trigo sp. nov.; female from Argentina, Salta, between Alemanía and Cafayate (ZFMK Arg206). A, female spinnerets. B, female palpal tarsal organ. C, tarsal organ on female right tarsus 4. D, ‘regular’ hairs on female abdomen. E, hairs on female anal cone. F, left female chelicera, lateral view (note absence of stridulatory file). G, epigynum, ventral view. H, female ALS. Scale lines: 20 µm (A, F), 2 µm (B, C), 10 µm (D, E, H), 100 µm (G).

Figure 29. Nerudia ola sp. nov.; male and female from Argentina, San Juan, San Agustín de Valle Fértil (ZFMK Arg141). A, female prosoma, frontal view. B, left procursus tip, prolateral-dorsal view. C, stridulatory file on male chelicera. D, lateral view of female chelicera, showing absence of stridulatory file. E, stridulatory pick (modified hair) on male palpal femur. F, right male cheliceral apophysis, frontal view. G, processes on male sternum. H, male gonopore. Scale lines: 100 µm (A, G), 10 µm (B, D, F, H), 20 µm (C), 2 µm (E).

Figure 30. Nerudia ola sp. nov.; male and female from Argentina, San Juan, San Agustín de Valle Fértil (ZFMK Arg141). A, male right tibia 1, retrolateral view. B, male metatarsus 4 with trichobothrium. C, male palpal tarsal organ. D, tip of right female palp, dorsal view; arrow points at tarsal organ. E, tarsal organ on male tarsus 2. F, epigynum, ventral view. G, male ALS and PMS. H, female ALS. Scale lines: 10 µm (A, B, D, G, H), 2 µm (C, E), 100 µm (F).

Figure 32. Nerudia nono sp. nov.; paratype female from Argentina, Córdoba, 5 km E Nono (ZFMK Ar 23910). A, abdomen and epigynum, ventral view. B, median structures in internal genitalia. C, D, cleared genitalia, ventral and dorsal views. Scale lines: 0.2 mm (A, C, D), 0.1 mm (B).

Figure 45. Sample of typical Nerudia habitats in Argentina. A, Jujuy, between San Salvador and Purmamarca (type locality of N. colina sp. nov.). B, Salta, NW of Campo Quijano (type locality of N. poma sp. nov.). C, Catamarca, near Paso de San Francisco (type locality of N. centaura sp. nov.). D, San Juan, W of Las Flores (type locality of N. rocio sp. nov.). E, La Rioja, SE of Aimogasta (N. ola sp. nov.). F, Córdoba, near Nono (type locality of N. nono sp. nov.).