Fresiax fray, Porto & Derkarabetian & Giribet & Pérez-González, 2024

Porto, Willians, Derkarabetian, Shahan, Giribet, Gonzalo & Pérez-González, Abel, 2024, Systematic revision of the South American “ Nuncia ” (Opiliones, Laniatores, Triaenonychidae), ZooKeys 1207, pp. 1-149 : 1-149

Fresiax fray sp. nov.

Figs 11 , 12 , 13 , 14 , 15 , 16

Material examined.

Holotype. ♂ Chile. Coquimbo: Bosque de Fray Jorge , E. Maury coll. 03. XI. 1988 ( MNHNCL) . Paratypes. Chile. Coquimbo: Limarí, Bosque Fray Jorge , P. N. Fray Jorge, E. Maury coll. 03. XI. 1988, 38 ♂ 24 ♀, amm. ( MACN) .

Additional material.

Chile: Coquimbo: Limarí, Bosque Talinay, P. N. Fray Jorge, relict Valdivian fog forest, R. Schuh, N. Platnick coll., 08. II. 1986, 66 specimens ( AMNH).

Etymology.

The epithet fray , a noun in apposition, refers to the type locality of the species, Bosque Fray Jorge National Park.

Diagnosis.

This species can be easily distinguished from the other species of the genus by its small size (<2 mm long), conical ocularium, with an apophysis at an angle of 45 °.

Distribution.

Chile, Coquimbo Region (Fig. 4 A ).

Description of male.

Measurements: Total length 1.81, carapace length 0.69, dorsal scutum length 1.47, carapace max. width 1.14, mesotergum max. length 1.49. Appendage measurements: Pedipalps. Length of trochanter 0.13, length of femora 0.80, length of patella 0.46, length of tibia 0.53, length of tarsus 0.62. Leg I: trochanter (tr) 0.16, femora (fe) 0.74, patella (pa) 0.38, tibia (ti) 0.51, metatarsus (mt) 0.62, tarsus (ta) 0.46. II: tr 0.22, fe 1.03, pa 0.41, ti 0.80, mt 0.98, ta 0.93. III: tr 0.19, fe 0.68, pa 0.36, ti 0.60, mt 0.67, ta 0.62. IV: tr 0.26, fe 1.04, pa 0.46, ti 0.80, mt 1.11, ta 0.57.

Dorsum (Fig. 11 , 12 ). Eta (η) hourglass-shaped dorsal scutum. Ocularium conical, with a small, forward-pointing apical spine and small setae. Eyes located on the distal region of the ocularium. Dorsal scutum microgranulate with no clear area delimitation. Areas I – III with two small setiferous granules, IV with three, posterior margin with a row of small setiferous granules. All free tergites with a row of small setiferous granules.

Chelicerae (Fig. 13 A, B ). Segment I characterized by a smooth surface without any prominent tubercles or setae. In contrast, segment II with a small frontal tubercle and covered in setae. Segment II with more pronounced texture and setal coverage compared to the smooth surface of segment I.

Pedipalps (Fig. 13 C, D ). Trochanter with a dorsal and a ventral spine, both with setae. Femora with a row of four dorsal spines with subdistal setae, a row of five ventral spines with setae, the proximal one with a subtriangular shape; two dorsal and distal tubercles with setae, a row of five small mesal tubercles with setae, and three small distal tubercles with setae. Patella with two rows of three tubercles with setae, two small mesal tubercles with setae, and few ventral granules. Tibia with four ectal and mesal spines with subdistal setae; three ventral tubercles with setae and two rows of 4–5 granules with setae on the dorsal surface. Tarsus with three mesal and ectal spines with subdistal setae, as well as few setae and granules.

Legs (Fig. 14 ). Coxa I bearing small setiferous tubercles and a row of three long tubercles with subdistal setae; II – IV with microgranulation, bearing 4–6 bridges between legs II and III, five or six between III and IV, six or seven between leg IV and the opisthosoma. Spiracles not visible. Smooth area occupies 1 / 3 of the leg II, almost ½ of III, and only a small proximal portion of the leg IV. Smooth area of leg II with five small setiferous tubercles, III with a row of four and an anterior process directed to the sternum. Sternum arrow-shaped, with a triangular posterior area. Leg I trochanter with three small ventral setiferous tubercles and one dorsal tubercle. Femora of leg I with a row of seven setiferous tubercles and a dorsal row of small setiferous tubercles. Tibia of leg I with 3–4 ventral tubercles with setae. Legs II – IV covered in setae, with the tarsus and calcaneus area densely covered in setae. Calcaneus smaller than astragalus, ≥ 4 × smaller in leg I, 5 × smaller in leg II, 8 × smaller in leg III, and 7 × smaller in leg IV. These differences in size ratios between the calcaneus and astragalus serve as distinguishing characteristics among the legs of this species. Tarsal count 3–6 – 4 – 4.

Penis (Figs 15 , 16 ). Pars distalis with a ventral plate and a prominent cleft that divides the plate into two lamellae. Each lamella is equipped with three macrosetae on the ventral surface and one macroseta on the dorsal surface. Capsula externa nearly as long as the capsula interna, having a notch that divides the capsula externa into two halves.

Female. Similar to male, with shorter pedipalpal femora.

Female measurements. Total length 1.54, length of carapace 0.61, length of dorsal scutum 1.31, max. width of carapace 0.96, max. width of mesotergum 1.35. Appendage measurements: Pedipalps. Length of trochanter 0.11. Length of femora 0.58, length of patella 0.37, length of tibia 0.45, length of tarsus 0.46. Leg I: trochanter (tr) 0.18, femora (fe) 0.62, patella (pa) 0.33, tibia (ti) 0.46, metatarsus (mt) 0.53, tarsus (ta) 0.42. II: tr 0.18, fe 0.88, pa 0.34, ti 0.71, mt 0.84, ta 0.86. III: tr 0.18, fe 0.62, pa 0.26, ti 0.53, mt 0.68, ta 0.49. IV: tr 0.21, fe 0.80, pa 0.37, ti 0.73, mt 0.98, ta 0.57.

Figures

Figure 3. Phylogenetics relationships of Triaenonychidae, with clade names as discussed in the main text. Phylogeny is derived from the IQ-TREE analysis. Nodes without circles have < 95 % bootstrap support to AH-aLR and UFBoot.

Figure 4. Maps showing the distribution of the species used in this work. South America (Chile and western Argentina inset). Chile in green, Argentina / South America in grey. Terrestrial ecoregions (following Olson et al. 2001) highlighted in yellow (Chilean Matorral) and orange (Valdivian temperate forests).

Figure 11. Fresiax fray sp. nov. habitus, male A dorsal view C lateral view E ventral view. Female B dorsal view D lateral view F ventral view. Scale bars: 500 µm. Species of Clade A, see Fig. 3.

Figure 12. Fresiax fray sp. nov. male, SEM images of habitus A dorsal view B lateral view C, D ventral view. Scale bars: 500 µm (A, B, C); 200 µm (D).

Figure 13. Fresiax fray sp. nov. chelicerae: mesal A ectal B pedipalps: mesal C ectal D. Scale bars: 200 µm.

Figure 14. Fresiax fray sp. nov. legs I A II B III C IV D. Scale bars: 200 µm (A, C); 500 µm (B, D).

Figure 15. Fresiax fray sp. nov. penis: ventral A, B apical C lateral D, E dorsal F, G. Scale bars: 100 µm (A, D, F); 20 µm (B, C, E, G).

Figure 16. Fresiax fray sp. nov. penis: ventral A apical B lateral C dorsal D. Colors: ventral plate (yellow), capsula externa (blue), capsula interna (red). Scale bars: 20 µm.