Medionops, Sánchez-Ruiz, Alexander & Brescovit, Antonio D., 2017

Sánchez-Ruiz, Alexander & Brescovit, Antonio D., 2017, A new genus with seven species of the Subfamily Nopinae (Araneae, Caponiidae) from the Neotropical region, Zootaxa 4291 (1), pp. 117-143 : 119-122

Medionops new genus

Type species. Medionops blades new species.

Other species included. Medionops cesari (Dupérré) n. comb., Medionops claudiae n. sp., Medionops murici n. sp., Medionops ramirezi n. sp., Medionops simla (Chickering) n. comb. and Medionops tabay n. sp.

Etymology. The generic name is a combination of the words Medio (= meaning half in Spanish) and Nops , and is masculine in gender.

Diagnosis. Members of the genus can be distinguished from all currently known nopine genera Cubanops Sánchez-Ruiz, Platnick, Dupérré , Nops MacLeay , Nopsides Chamberlin , Nyetnops Platnick & Lise , Orthonops Chamberlin and Tarsonops Chamberlin by the shape of the endites with acute lateral projections extending dorsally on the outer sides ( Figs 2 E, 20C), by the crista being extremely short, almost unnoticeable ( Figs 3 G, J; 15E, F) or absent ( Figs 9 K; 11D; 13B, C), and by having all pretarsi with elongated and dorsally reflexed unpaired claws, associated with a large and globose arolium ( Figs 1E ; 3B, C, D; 4A, B, D; 5H, J, K; 9E, F; 11B, G, J–L; 13D, E).

Description. Medium–sized caponiids with two eyes ( Figs 2 B, C). Carapace uniformly orange, elongate, oval, widest at rear of coxae II, only gradually narrowed anterior of eyes ( Figs 6 A,B); pars cephalica not elevated; pars thoracica slightly sloping posteriorly, with slight submarginal depressions opposite intercoxal spaces ( Fig. 2 A); few dorsally directed strong bristles on clypeus ( Fig. 2 B); thoracic groove absent. Eyes dark, situated on slightly elevated black ocular tubercle, separated by about half of its diameter ( Fig. 2 C), set back from anterior margin of clypeus by about twice their diameter ( Fig. 2 B). Chelicerae orange, with median lamina; most of distance between lamina and fang base occupied by white membranous lobe; cheliceral paturon with scattered, long, weak bristles; ectal side with stridulatory ridges ( Fig. 2 G); pick on prolateral side of palpal femur, situated near proximal end of podomere ( Fig. 19C ). Endites orange except anterior tips with white membranous projection ( Figs 10 C; 20C), wide, convergent along midline but not touching, with middle part slightly wider than distal and proximal, with acute projections extending dorsally on the outer sides (arrows in Figs 2 E; 20C), covered with scattered long setae, and with strong distal serrula consisting of a single tooth row ( Fig. 2 F). Labium orange, broad, rounded, fused to sternum along posterior groove, rebordered in apical part ( Figs 2 D–E; 10C; 20C). Sternum orange, oval, surface with numerous long, stiff setae ( Fig. 2 D); pleural membrane with three sclerotized intercoxal extensions between coxae I and II, II and III, and III and IV, long precoxal triangles on coxae II–IV ( Fig. 10 C). Legs orange, formula 4123, without spines; metatarsi entire, with dorsal metatarsal stopper ( Figs 3 D, F; 4E; 11F; 15C), anterior legs with crista extremely short, not reaching one fourth of metatarsus length ( Figs 3 G, J), or almost unnoticeable ( Figs 15 B– F), or completely absent as in the Brazilian species M. claudiae n. sp. ( Figs 9 J–K) and M. murici n. sp. ( Figs 11 C,D,F; 13B,C); gladius with the traditional shape among nopine ( Figs 3 D, G, J; 5G; 9K; 15E), but almost unnoticeable or absent in M. murici n. sp. ( Figs 11 C, D, F; 13B, C); all tarsi bisegmented ( Figs 3 B, D; 4A, E; 5G; 9E; 11A, B); pretarsus with three claws, paired claws usually with 5–8 teeth, most distal of which are largest ( Figs 1E ; 3B,E; 4D; 5J; 9E; 13D), unpaired claws elongated, dorsally reflexed on all legs, without teeth ( Figs 3 C; 4D, G, H; 11J–L) with small projections of the cuticle distributed dorsally on proximal part ( Fig. 4 H); unpaired claws associated with large, globose translucent arolium on all legs ( Figs 1E ; 3B, C, D; 4A, B, D; 5H, J, K; 9E, F; 11B, G, J–L; 13D, E); with numerous ventral frictional setae on tarsi ( Figs 3 B, E; 4D; 5J; 9E, F, I; 11J; 13F, H), several other setae around pretarsal claws ( Figs 9 F–H; 13E, F, G, I). Sense organs scanned only in M. blades n. sp. and M. murici n. sp. Tibiae, metatarsi, and tarsi with trichobothria in single row ( Figs 11 A, E), bases with semicircular rim bearing slight longitudinal ridges ( Figs 3 H; 4I); tarsal organ exposed, roundish, with marginal ring slightly pronounced ( Figs 3 I, L; 4C, F; 11H–I); slit sensillae on tibiae, metatarsi and tarsi. Male and female palpal tarsus elongated, without claw, retrolateral and ventral surfaces densely covered with strong setae; with oval pad of fine chemoreceptor setae on dorsal, distal part ( Figs 5 I, L; 7C, F; 19I), with a tibial brush on prolateral side of palp, near distal end ( Figs 2 I; 5I; 7B; 9A; 12B; 19B, L). Abdomen dorsally with pattern of lines, spots, chevrons or bands; almost unnoticeable in M. tabay n. sp. and M. ramirezi n. sp.; ventrally immaculate ( Figs 10 B; 20B), lighter, with only slightly sclerotized epigastric and postepigastric scutum, with two pairs of respiratory spiracles clustered around epigastric groove; anterior spiracles leading to wide, short tracheal trunk ending in numerous long tracheoles; posterior spiracles leading to two large tracheal trunks extending anteriorly into cephalothorax (inner trunks connected), plus single, much narrower trunk extending posteriorly for most of abdominal length and few short, small tracheoles extending posteriorly ( Figs 4 J–L, 7G–I, 13J–L, 16G–I). Six spinnerets in typical caponiid arrangement ( Figs 5 A, 12G), ALS with a single, major ampullate gland spigot in males ( Figs 5 C, 12H), PMS with 7–8 ampullate gland spigots ( Figs 5 E–F, 12I) and PLS with 10–12 ampullate gland spigots ( Figs 5 A–B, 12G). Male palpal morphologywith short patella; tibia excavated ventrally; cymbium elongated, not swollen, distal surface acuminate; bulb globose, oval, originating near proximal ventral surface of cymbium, with very long embolus ventrally directed, protruding dorsally from proximal–posterior prolateral surface of bulb making strong curvature near its base toward ventral part of animal ( Figs 6 D; 8D; 10D; 14D; 17D; 18D; 20D), with elaborate tip. External female genitalia with a weakly sclerotized anterior plate, strong sclerotization around spiracles and on outer ends of posterior receptaculum (noticeable by transparency) ( Figs 6 C; 8C; 14C; 17C; 18C). Internal female genitalia consisting of transverse, wide, anteriorly directed, weakly sclerotized receptaculum (r); most of species with sinuous distal margin of receptaculum (dmr) with median concavity (mc); proximal margin associated with a dorsally projected internal fold (if), sometimes along with posterior plate (pp); uterus externus (ue) anterior to receptaculum, membranous and anteriorly directed ( Figs 4 J–L, 7G–I, 13J–L, 16G–I).

Distribution. South America and Panamá ( Fig. 21 ).

Figures

FIGURE 1. A – E Schematic drawings of the left females legs of three Nopinae genera, prolateral view; setae, trichobothria, membranes and sensillae were omitted. F – H Schematic drawings of labium and endites. A – C, G Nops guanabacoae MacLeay from Cuba (BIOECO 576). D, H Nopsides ceralbonus Chamberlin from Mexico (CIB 3340). E, F Medionops blades n. sp. from Colombia, paratype. A metatarsus, tarsus and pretarsus I, lateral view. B tarsus and pretarsus I, apical view. C tarsus and pretarsus IV, apical view. D tarsus and pretarsus I, apical view. E tarsus and pretarsus I, apical view. Abreviations: ar—arolium, ca—crista, gl –– gladius. Scale bar: 0.5 mm.

FIGURE 2. Medionops blades n. sp., male from type locality (AMNH). A carapace, lateral view. B clypeus, lateral view. C carapace, dorsal oblique view. D sternum and mouthparts, ventral view. E labium and endites, ventral view (arrows point to the acute projections). F serrula, ventral oblique view. G chelicerae, lateral view. H left palp, prolateral view. I tibial brush, prolateral view. J tip of palpal embolus, prolateral view (arrow points to the blade – shaped projection). K tip of palpal embolus, retrolateral view (arrow point at blade – shaped projections). L detail from tip of palpal embolus, retrolateral view.

FIGURE 3. Medionops blades n. sp., male from type locality (AMNH). A left leg I, prolateral view. B tarsus on left leg I, prolateral view. C tarsal claws on left leg I, dorsal view. D tarsus on left leg II, prolateral view. E tarsal claws on left leg II, prolateral view. F join of tarsus and metatarsus on left leg II, dorsal oblique view. G metatarsus on left leg II, ventral view. H trichobothrial base on left leg II, dorsal oblique view. I tarsal organ on left leg II, dorsal view. J metatarsus on right leg I, ventral view. K base of setae on right tarsus I, prolateral oblique view. L tarsal organ on right leg I, dorsal view. Abbreviations: ajadesmatic joint, ar—arolium, ca—crista, gl—gladius, MtS—Metatarsal stopper.

FIGURE 4. Medionops blades n. sp., A – I male from type locality (AMNH), J – L female from type locality (AMNH). A tarsus on left leg III, prolateral view. B tarsal claws on left leg III, dorsal oblique view. C tarsal organ on left leg III, dorsal view. D tarsal claws on left leg IV, prolateral view. E tarsus on left leg IV, prolateral view. F tarsal organ on left leg IV, dorsal view. G tarsal claws on left leg IV, retrolateral oblique view. H detail of unpaired claw of left leg IV, retrolateral oblique view. I trichobothrial base on left metatarsus IV, dorsal oblique view. J internal genitalia, dorsal view. K internal genitalia, anterior view. L internal genitalia, posterior view. Abbreviations: aj—adesmatic joint, ar—arolium, ap—anterior plate, dmr—distal margin of receptaculum, if—internal fold, mc—median concavity, re—receptaculum, pp—posterior plate, t—tracheal trunk, ue—uterus externus.

FIGURE 5. Medionops blades n. sp., female from type locality (AMNH). A spinnerets, ventral view. B left PLS, ventral view. C left ALS, ventral view. D aciniform gland spigot on left PLS, lateral oblique view. E left PMS, ventral view. F right PMS, ventral view. G tarsus on left leg I, prolateral view. H tarsal claws on left leg I, prolateral view. I left palp, prolateral view. J tarsal claws on left leg IV, retrolateral view. K tarsal claws on left leg IV, retrolateral oblique view. L left palp, ventral oblique view. Abbreviations: ar—arolium, CwL—claw lever, CwS—claw slit sensilla, gl—gladius.

FIGURE 6. Medionops blades n. sp. A male holotype, habitus, dorsal view. B female paratype, habitus, dorsal view. C external genitalia of female paratype, ventral view. D left palp of male holotype, prolateral view. E left palp of male holotype, retrolateral view. Abbreviations: ap—anterior plate, ess—external sclerotization around spiracles, go—genital opening, ppposterior plate.

FIGURE 9. Medionops claudiae n. sp., A – C Male paratype (IBSP 19458), D – L Male from Caraíva, Brazil (IBSP 36569). A left palp, prolateral view. B tip of left embolus, posterior view. C same, prolateral view. D same, retrolateral view. E tarsal claws on left leg IV, prolateral view. F tarsal claws on left leg I, prolateral view. G setae on left tarsus I, prolateral apical view. H same, detail of setae, prolateral apical view. I same, detail of frictional setae, prolateral apical view. J metatarsus on left leg I, ventral view. K metatarsus on left leg I, ventral apical view. L join between metatarsus and tibia, ventral view. Abbreviation: CwS—claw slit sensilla, gl—gladius.

FIGURE 10. Medionops claudiae n. sp., male holotype (IBSP 17717). A habitus, dorsal view. B habitus, ventral view. C sternum and mouthparts, ventral view. D left palp, prolateral view. E left palp, retrolateral view.

FIGURE 11. Medionops murici n. sp., male (IBSP 85199). A tarsus on left leg I, retrolateral view. B tarsal claws on left leg I, retrolateral view. C join of tarsus and metatarsus on left leg I, ventral view. D detail of join of tarsus and metatarsus on left leg I, ventral view. E left leg II, retrolateral view. F join of tarsus and metatarsus on left leg II, ventral oblique view. G tarsal claws on left leg II, retrolateral view. H tarsal organ on left leg II, dorsal view. I tarsal organ on left leg IV, dorsal view. J tarsal claws on left leg IV, retrolateral view. K tarsal claws on left leg IV, dorsal view. L detail of tarsal claws on left leg IV, dorsal view.

FIGURE 15. Medionops ramirezi n. sp., male (MNRJ 6371). A left leg I, prolateral oblique view. B join of tarsus and metatarsus on left leg I, prolateral oblique view. C join of tarsus and metatarsus on left leg I, prolateral view. D metatarsus on left leg II, ventral oblique view. E join of tarsus and metatarsus on left leg II, ventral oblique view. F detail of the crista, ventral oblique view. Abbreviations: ca—crista, gl—gladius.

FIGURE 19. A – F Medionops simla (Chickering) new comb, left palp of male from Arima (AMNH). G – L Medionops tabay n. sp., left palp of male from La Montaña, Mérida (AMNH). A prolateral view. B tibial brush, prolateral view. C stridulatory pick at base of palpal femur, prolateral view. D tip of embolus, prolateral view. E tip of embolus, dorsal oblique view. F tip of embolus, dorsal view. G prolateral view. H ventral view. I detail of chemosensory setae path from cymbium, prolateral view. J tip of embolus, prolateral view. K tip of embolus, ventral view. L tibial brush, prolateral view.

FIGURE 21. Map of South America showing distribution of Medionops species. Triangle, Medionops blades n. sp.; plus sign, Medionops cesari (Dupérré) n. comb.; square, Medionops claudiae n. sp.; tears, Medionops murici n. sp.; diamond, Medionops ramirezi n. sp.; circles, Medionops simla (Chickering) n. comb.; heart, Medionops tabay n. sp.