A new caponiid genus, Nyetnops, is described to contain a remarkable new species, N. guarani from Brazil. These spiders, which have a bizarrely elongated male palp, have the subsegmented tarsi typical of the Nopinae, but lack the additional leg modifications found in those taxa. They may therefore represent the sister group of the other described nopine genera.
Introduction
The present paper, the fifth in a series on the spider family Caponiidae, is the second to deal with members of the Nopinae, a seemingly monophyletic group whose members are easily recognized by their subsegmented tarsi (there is at present no evidence that the remaining, non-nopine genera, the so-called Caponiinae, constitute a single monophyletic group). The type genus, Nops MacLeay (1839), is also marked by a variety of additional, bizarre leg modifications, including the enormous elongation of the unpaired claw into a structure that reaches as far dorsally as do the paired claws (and is apparently associated with the presence of a translucent pulvillar lobe), the elaboration of a translucent keel under the anterior metatarsi (Platnick, 1995: figs. 6, 7), and the presence of a distal, translucent, fan-shaped extension of the intersegmental membrane separating the anterior metatarsi and tarsi (Platnick: 1995, figs. 8–11).
The new Brazilian species treated here (figs. 1, 2) has subsegmented tarsi but none of the other leg modifications found in Nops. As the other known nopine genera (Orthonops, Tarsonops, and Nopsides, all described by Chamberlin, 1924) all share at least some of those additional leg modifications, it seems likely that this new species, which we assign below to the new genus Nyetnops, represents the sister group of all the other described nopines. We have seen specimens of a few other apparently undescribed Neotropical species that may prove to be members of Nyetnops (or at least other basal nopine genera), but better samples of those taxa, and additional study, will be needed to determine their status.
Figs. 1, 2.
Nyetnops guarani, new species, male cephalothorax and abdomen. 1. Dorsal view. 2. Ventral view.
Although the legs of the Brazilian species are relatively unmodified (for a nopine), the male palp is extraordinary (figs. 3–5). Not only is the embolus elongated, thickened, protruding, and distally widened, the entire bulb has become so elongated that the limits of the embolus per se can be discerned only by differences in the cuticle (figs. 25–28).
Figs. 3–6.
Nyetnops guarani, new species. 3. Left male palp, prolateral view. 4. Same, ventral view. 5. Same, retrolateral view. 6. Internal female genitalia, dorsal view.
The available specimens are also of interest because they may help resolve a puzzle with regard to the genus Caponina Simon (1891). Brignoli (1977) reported on a series of specimens collected at Nova Teutonia, Santa Catarina, Brazil, by F. Plaumann, which he attributed to Bruchnops melloi Birabén (1951), now placed as a junior synonym of Caponina notabilis (Mello-Leitão, 1939). That series included various adults and juveniles that were reported to have either six, four, or two eyes. During a revision of Caponina (Platnick, 1994a) a few specimens were encountered with teratological eye numbers (three or five), but no two-eyed specimens of that genus were found in any of the samples examined then (or subsequently).
In connection with the present revision, we received for study from the Institut Royal des Sciences Naturelles de Belgique, Brussels, a sample of caponiids also collected at Nova Teutonia by Plaumann, which proved to be a mixed lot. Some of the material did indeed belong to C. notabilis, as expected, but one female, which has only two eyes, belongs instead to the new species treated here. This suggested that Brignoli's series may also have been mixed, that his two-eyed specimens actually belong to Nyetnops, and that there are actually no two-eyed Caponina.
The difficulty with this hypothesis is that Brignoli (1977: 610) indicated that the only adult female he examined (collected in November, 1958) has only two eyes. Through the courtesy of Drs. Bernd Hauser and Peter Schwendinger, we have now also been able to re-examine some of the specimens from the Muséum d'Histoire Naturelle, Geneva, that were studied by Brignoli. His adult female is correctly identified, but clearly has six eyes, rather than two; on the other hand, at least one of the two-eyed juveniles clearly has subsegmented anterior tarsi, and hence cannot possibly belong to C. notabilis. Thus, there seems no doubt that the two genera do indeed co-occur at Plaumann's locality.
The material reported on below comes from the collections of the American Museum of Natural History (AMNH), the Institut Royal des Sciences Naturelles de Belgique, Brussels (IRSN, courtesy of Dr. Léon Baert), the Museu de Ciências Naturais, Porto Alegre (MCN, courtesy of Dr. Erica Buckup), the Museu de Ciências e Tecnologia da Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre (MCTP), and the Museu de Historia Natural do Capão da Imbuia, Curitiba (MHCI, courtesy of Drs. Ricardo Pinto-da-Rocha and Antonio Brescovit). Assistance with illustrations and plates was supplied by Mohammad Shadab, Estevam Luís Cruz da Silva, and Steve Thurston. All measurements are in millimeters.
Systematics
Nyetnops, new genus
Etymology
The generic name is an arbitrary combination of letters, masculine in gender because of the ending -ops.
Diagnosis
Members of the genus can be separated from the previously known caponiid genera as follows: from Caponia Simon (1887), Calponia Platnick (1993), Diploglena Purcell (1904), Caponina, Notnops Platnick (1994b), Taintnops Platnick (1994b), and Tisentnops Platnick (1994b) by the presence of subsegmented tarsi, from Nopsides by having only two eyes, from Nops by having normal, rather than greatly elongated, unpaired tarsal claws, from Tarsonops by having entire metatarsi and only two tarsal subsegments, and from Orthonops by lacking a metatarsal keel and a process extending from the intersegmental membrane between the metatarsi and tarsi of legs I and II.
Description
Small caponiids with carapace light orange, bearing paler yellow markings in labyrinthine arrangement (fig. 1), oval, widest at front of coxae III, only gradually narrowed anterior of eyes; pars cephalica elevated at rear (more so in males than in females), without elevated ocular tubercle; pars thoracica high anteriorly, steeply sloping posteriorly, with only very slight submarginal elevations opposite coxal bases, separated by very slight submarginal depressions opposite coxal interspaces; cuticle mostly smooth, with low sculpturing consisting of roughly hexagonal cells restricted to area of thoracic groove, with few long, dark setae in ocular area and on pars cephalica; thoracic groove obsolete; clypeus without pair of rounded elevations at lateral corners, almost three times as high as eyes. Two large, dark eyes separated by less than their diameter, posterior margins situated at about one–eighth of carapace length, united by oval ring of black pigment. Chelicerae with median lamina terminating in toothlike tip; distal half of median edge of paturon occupied by white membranous lobe; lateral surface flattened, with long series of stridulatory ridges (figs. 7, 8); pick for stridulatory ridges at base of prolateral side of palpal femur (figs. 3, 9). Endites (figs. 10, 11) light orange, wide, strongly convergent, not protuberant posteriorly, rounded distally, males with protuberant anterolateral corners (fig. 2), anterior surface distally with strong serrula consisting of single tooth row (fig. 12), proximally without strong setae originating from enlarged bases. Labium light orange, broad, triangular, fused to sternum along deep posterior groove. Sternum light orange, oval, cuticle glabrous, bearing scattered weak setae; cephalothoracic membranes with three weakly sclerotized epimeric sclerites dorsal of coxae I, II, and III plus IV; sternal margin rebordered, with long, triangular extensions reaching to middle of coxae II–IV and shorter intercoxal projections; epimeric sclerites not fused with sternal extenstions. Female palpal tarsus only very slightly expanded, without claw, with numerous long setae, including conspicuous, dense patch of setae prolaterally and dorsal pad of shortened setae. Leg formula 4123; legs orange, without spines, with many setae; cuticle ridged, granulate (fig. 23); metatarsi entire, without translucent median, longitudinal keel or distal, translucent, fan-shaped extension originating from intersegmental membrane (figs. 13, 14); tarsi subsegmented (fig. 14), proximal subsegment slightly longer than distal one; tarsi with three claws (figs. 15–18); paired claws with about 7–9 teeth, most distal of which are largest (tooth number varies among legs, and between pro- and retroclaw of each leg); unpaired claw without teeth, distinctly protruding from onychium. Tarsal organ exposed, with concentric ridges (fig. 24); metatarsi with slit sense organs near depressed area bearing tiny, central pore (figs. 21, 22); trichobothria (figs. 19, 20) present on tibiae, metatarsi, and tarsi, their bases with semicircular rim bearing slight longitudinal ridges. Abdomen pale gray dorsally, with hairline pale markings, lighter ventrally, with two pairs of respiratory spiracles clustered around epigastric groove, tracheal arrangement unknown. Spinnerets in typical caponiid arrangement; judging from light microscopy only, anterior laterals apparently with single large major ampullate gland spigot and two smaller piriform gland spigots in female, male with only major ampullate gland spigot evident; posterior medians apparently with 3–5 long-shafted aciniform gland spigots, females with enlarged, posteriorly situated single wide spigot; posterior laterals with several aciniform gland spigots. Male palpal femur without dorsal tubercle; patella short; tibia not excavated ventrally, distal promargin with short row of stiff, pale setae; cymbium (figs. 29, 30) only slightly swollen, with distinct dorsal pad of short setae; palpal bulb longer than cymbium, distinction evident between bulb and embolus only by differences in cuticular surface (figs. 25–28). Internal female genitalia consisting of membranous, transverse anterior receptaculum bearing lateral sclerotized elements, without median receptaculum extending posteriorly (fig. 6).
Figs. 7–12.
Nyetnops guarani, new species, male. 7. Chelicera, oblique anterior view. 8. Cheliceral striculatory ridges, oblique lateral view. 9. Stridulatory pick on palpal femur, prolateral view. 10. Endite, anterior view. 11. Endite, posterior view. 12. Serrula, oblique posterior view.
Figs. 13–18.
Nyetnops guarani, new species, male. 13. Metatarsus and tarsus I, dorsal view. 14. Same, lateral view. 15. Claws of leg I, lateral view. 16. Same, detail. 17. Claws of leg IV, lateral view. 18. Setae accompanying claws of leg IV, lateral view.
Types
Male holotype and female allotype from Fóz do Córrego Três Barras, Rio Guarani, Três Barras do Paraná, Paraná, Brazil (Feb. 24–Mar. 24, 1993; A. B. Bonaldo), deposited in MCN.
Diagnosis
The enormously elongated palpal bulb of males (figs. 3–5, 25–28) and the anteriorly excavated lateral epigynal sclerotizations of females (fig. 6) are diagnostic.
Male (holotype): Total length 3.27. Carapace 1.31 long, 1.22 wide, pale orange with pair of large, prominent, longitudinal lighter markings on elevated portion at rear of pars cephalica, in labyrinthine pattern elsewhere on carapace. Endites with distinctly protruding anterolateral corners. Abdomen with hairline pale markings. Palpal tibia with promarginal row of stiff setae; entire bulb enormously elongated (figs. 3–5, 25–28).
Female (allotype): Total length 3.46. Carapace 1.34 long, 1.18 wide. Coloration as in male. Endites without protruding corners. Internal genitalia with low sclerotized triangles situated near origin of posterior tracheae (fig. 6).
Other Material Examined
BRAZIL: Paraná: Fóz do Córrego Três Barras, Rio Guarani, Três Barras do Paraná, Feb. 24–Mar. 24, 1993 (A. B. Bonaldo, MCN 23414, AMNH), 17♂; Foz do Rio Capoteiro, Pinhão, Oct. 25, 1991 (R. Pinto-da-Rocha, M. R. Lopes, MHCI), 1♂; Usina Hidrelétrica, Reserva Rio dos Touros, Pinhão, Feb. 22, 1992 (R. Pinto-da-Rocha, MCN 25919), 3♂, Mar. 1992 (R. Pinto-da-Rocha, MHCI), 1♂; Usina Hidrelétrica, Ribeirão Estreito, Pinhão, Jan. 21–Feb. 1992 (R. Pinto-da-Rocha, MHCI), 3♂, Mar. 1992 (R. Pinto-da-Rocha, M. Segalla, MCN 25918, 25920), 8♂. Rio Grande do Sul: Vicente Dutra, all pitfalls, T. F. Trescher: Jan. 8, 2006 (MCTP 19528), 3♂, 1♀, Jan. 23, 2006 (MCTP 19529), 15♂, 3♀, Feb. 7, 2006 (MCTP 19530), 7♂, Feb. 22, 2006 (MCTP 19531), 6♂, Mar. 9, 2006 (MCTP 19532), 9♂, 2♀. Santa Catarina: Nova Teutonia, Aug. 1957 (F. Plaumann, IRSN), 1♀.
