Fresiax conica, 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 conica sp. nov.

Figs 5 , 6 , 7 , 8 , 9 , 10

Material examined.

Holotype. ♂ Chile. Choapa: Cuesta Cavilolén , 31.76669 ° S, 71.32727 ° W, 300 m, M. Ramírez, A. Ojanguren, J. Pizarro coll. 11. II. 2011 ( MNHNCL) . Paratypes. Chile. Choapa: Los Vilos, Cuesta Caviolén , 30 km NE de Los Vilos, E. Maury coll., 1 ♀ 12. XII. 1987 ( MACN) . Choapa: Los Vilos, Cuesta Caviolén , 30 km NE de Los Vilos, E. Maury coll., 1 ♀ 12. XII. 1987 ( MACN) .

Etymology.

The term “ conica ” refers to the shape of the ocularium, which is conical and lacks an apophysis. The specific epithet was also a name “ in schedula ” by the late Dr. Emilio Maury that labeled the specimens. Maury early recognized this species as a new but never published. We keep the Maury’s specific name to maintain the name preference of the researcher who first recognized this species as new.

Diagnosis.

The conical ocularium, without acute apophysis, clearly distinguishes this species from others in the genus. There is only one row of tubercles on the anterior region of the dorsal scutum. The apical section of the tubular capsula interna is subtriangular.

Distribution.

Chile: Coquimbo Region (Fig. 4 A ).

Description of male.

Measurements: Total length 2.01, carapace length 0.78, dorsal scutum length 1.30, carapace max. width 1.05, mesotergum max. length 1.50. 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) 0.16, patella (pa) 0.74, tibia (ti) 0.38, metatarsus (mt) 0.51, tarsus (ta) 0.62. II: tr 0.46, fe 0.22, pa 1.03, ti 0.41, mt 0.80, ta 0.98. III: tr 0.93, fe 0.19, pa 0.68, ti 0.36, mt 0.60, ta 0.67. IV: tr 0.62, fe 0.26, pa 1.04, ti 0.46, mt 0.80, ta 1.11.

Dorsum (Fig. 5 , 6 ). Eta (η) or hourglass-shaped dorsal scutum ( Kury and Medrano 2016). Ocularium conical with a group of ~ 20 setiferous tubercles. Eyes located on the middle of the ocularium. Dorsal scutum microgranulate with a row of setiferous tubercles on each side of the ocularium, without clear delimitation of the mesotergal areas. Areas I – IV and posterior margin with seta, I with two, II and III with four, and IV and posterior margin with six. All free tergites bear a row of small, setiferous, rounded granules.

Chelicerae (Fig. 7 A, B ). Segment I with few sparse setae. Segment II with three small frontal tubercles and sparse setae.

Pedipalps (Fig. 7 C, D ). Trochanter with long ventral and dorsal spines. Femora bearing a remarkable ventral-proximal subtriangular spine with long subdistal setae; a row of four ventral spines, with subdistal setae and six dorsal small spines with setae. Patella bearing a notable mesal spine with long setae. There are two rows of small setiferous tubercles on the dorsal patella-tarsus. Tibia shows a ventral row of four long spines. Tarsus with three mesal and ectal setiferous spines.

Legs (Fig. 8 ). Coxa I with two rows of setiferous tubercles, the distal one with a subdistal setae. II – IV are microgranulate, with four bridges between the legs II and III, 6–8 bridges between the legs III and IV, seven between the leg IV and the opisthosoma. Spiracles not covered by bridges. The smooth surface represents <¼ of coxa and leg III. Sternum arrow-shaped. Legs I – IV covered in setae, tarsal area and calcaneus are also setose. Trochanter I with small ventral granules. Femora I with a row of nine dorsal and ventral setiferous tubercles. Calcaneus is shorter than astragalus (7 × shorter in leg I, 8 × in II, 13 × in III, 15 × in IV). Tarsal count 3–6 – 4 – 4.

Penis (Figs 9 , 10 ). Pars distalis has a large ventral plate with a cleft separating the plate into two lamellae. Each one bears three acute macrosetae on the ventral surface and one acute macroseta on the dorsal surface. Capsula externa is cleft and covers the dorsal and lateral surfaces. The Capsula interna is tubular with an apical subtriangular portion.

Female. Similar to male, with shorter pedipalpal femora.

Female measurements. Total length 1.91, length of carapace 0.76, length of dorsal scutum 1.29, max. width of carapace 1.04, max. width of mesotergum 1.47. Appendage measurements: Pedipalps. Length of trochanter 0.20, length of femora 0.76, length of patella 0.43, length of tibia 0.63, length of tarsus 0.56. Leg I: trochanter (tr) 0.26, femora (fe) 0.88, patella (pa) 0.38, tibia (ti) 0.56, metatarsus (mt) 0.64, tarsus (ta) 0.384. II: tr 0.23, fe 1.14, pa 0.53, ti 0.84, mt 0.90, ta 0.73. III: tr 0.22, fe 0.88, pa 0.36, ti 0.69, mt 0.88, ta 0.43. iv: tr 0.23, fe 1.07, pa 0.49, ti 0.95, mt 1.26, ta 0.61.

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 5. Fresiax conica sp. nov. male A dorsal view B lateral view C ventral view. Scale bars: 1 mm. Species of Clade A, see Fig. 3.

Figure 6. Fresiax conica 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 7. Fresiax conica sp. nov. chelicerae: mesal A ectal B pedipalps: mesal C ectal D. Scale bars: 200 µm.

Figure 8. Fresiax conica sp. nov. legs I A II B III C IV D. Scale bars: 200 µm (A, C); 500 µm (B, D).

Figure 9. Fresiax conica sp. nov. penis: ventral A, B apical C lateral D, E dorsal F, G. Scale bars: 200 µm (A, D, F); 20 µm (B, C, E, G).

Figure 10. Fresiax conica 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 (A, B); 50 µm (C, D).