Fresiax mauryi, 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 mauryi sp. nov.

Figs 17 , 18 , 19 , 20 , 21 , 22

Material examined.

Holotype. ♂ Chile. Monumento Natural Contulmo , 38.01501 ° S, 73.17981 ° W, 360 m, M. Ramírez & F. Labarque coll., 10. II. 2005 ( MNHNCL) . Paratypes. Chile. Cautín: Lago Caburgua, 39.20749 ° S, 71.80529 ° W, S. Peck J. Peck coll., 15. XII. 1984, 1 ♂ ( AMNH). Llanquihue: P. N. Alerce Andino, Correntoso, sendero Huillifoten, 41.58235 ° S, 72.61738 ° W, 135 m, M. Ramírez & F. Labarque coll., 03. II. 2005, 1 ♀ ( MACN). Malleco, Monumento Natural Contulmo, 38.01501 ° S, 73.17981 ° W, E. Maury coll., 13. I. 1989, 1 ♂ 1 ♀ ( MACN). Malleco: P. N. Nahuelbuta, 37.81477 ° S, 72.9967 ° W, M. Ramírez & F. Labarque coll., 12. II. 2005, 1 ♂ ( MACN). Malleco: Monumento Natural Contulmo, 38.01501 ° S, 73.17981 ° W, 360 m, M. Ramírez & F. Labarque coll., 10. II. 2005, 1 ♀ ( MACN), P. N. Nahuelbuta, 37.81477 ° S, 72.9967 ° W, M. Ramírez & F. Labarque coll., 12. II. 2005, 5 ♂ 13 ♀ 6 imm. ( MACN).

Additional material.

Chile. Malleco, Monumento Natural Contulmo, 38.01624 ° S, 73.17942 ° W, 361 m, G. Giribet, G. Hormiga, A. Pérez-González coll. 13. XI. 2014 ( MACN). Same locality, 38.01625 ° S, 73.17902 ° W, M. Ramírez, M. Izquierdo, P. Michalik, C. Wirkner, K. Huckstorf coll., 09. II. 2012, 1 imm. ( MACN). Caramávida, San Alfonso, Quebrada Caramávida, San Alfonso, Reserva Arauco, 37.70942 ° S, 73.17107 ° W, 750 m, 15. I. 2018, 1 ♀ ( MACN), Quebrada Caramávida, “ sector 9 ”, Reserva Arauco, 37.66839 ° S, 73.22683 ° W, 800 m, 16. I. 2018 ( MACN).

Etymology.

Patronym after the late Argentine arachnologist Emilio Maury, in honor of his contributions to the study of the Triaenonychidae (and Opiliones in general) of South America’s Southern Cone.

Diagnosis.

The prominent interocular apophysis, the carapace densely covered with rounded tubercles, the long tubercles of the mesotergum, the long drop-shaped genital operculum, the ectal-distal process of cheliceral segment II, and the hypertelic genitalia distinguish this species from all its congeners.

Distribution.

Chile: Araucanía Region (Fig. 4 A ).

Description of male.

Measurements: Total length 2.93, carapace length 0.97, dorsal scutum length 1.99, carapace max. width 1.40, mesotergum max. width 1.81. Appendage measurements: Pedipalps. Trochanter length 0.14, femora length 0.87, patella length 0.61, tibia length 0.66, tarsus length 0.56. Leg I: trochanter (tr) 0.25, femora (fe) 0.97, patella (pa) 0.42, tibia (ti) 0.73, metatarsus (mt) 0.90, tarsus (ta) 0.55. II: tr 0.29, fe 1.36, pa 0.43, ti 0.94, mt 1.55, ta 1.00. III: tr 0.28, fe 1.00, pa 0.41, ti 0.82, mt 1.24, ta 0.60. IV: tr 0.26, fe 1.33, pa 0.49, ti 1.11, mt 1.85, ta 0.72.

Dorsum (Fig. 17 , 18 ). Eta (η) hourglass-shaped dorsal scutum. Ocularium raised, with a long backward-bending apophysis between the eyes, covered with rounded tubercles and with few setae on the apophysis. Carapace densely covered in rounded tubercles, mesotergum with areas delimited by strong tubercles. Areas I and II with straight rows of four and five setiferous tubercles, respectively, and III and IV with a row of eight setiferous tubercles (the two central ones are stronger than others). Posterior margin with a row of 12–14 setiferous tubercles. Free tergites with a row of setiferous tubercles similar to the posterior margin of the dorsal scutum.

Chelicerae (Fig. 19 A, B ). Segment I with a small, granulated area on the dorso-distal surface and two ventral granules. Segment II with an ectal-distal process that bears a few setae.

Pedipalps (Fig. 19 C, D ). Trochanter with three small dorsal granules, and two ventral and a small dorsal tubercle. Granules cover the femora, patella, tibia, and tarsus. Femora with a row of five spines with one subdistal seta, the proximal one bifurcated. Patella with three mesal spines and one ectal spine with subdistal setae. Tibia with four ectal and mesal spines with subdistal setae. Tarsus with three ectal and mesal spines with subdistal setae.

Legs (Fig. 20 ). Coxae I – IV bearing small setiferous tubercles, leg I with three long subdistal setiferous tubercles, the distal one forked at its terminal end. Spiracles visible. A smooth area occupies ¼ of legs II (which has a tubercle with subdistal seta) and III. The drop-shaped genital operculum is larger than all species of the genus. Opisthosomal sternites with a row of small setiferous tubercles. Sternum reduced due to the large size of the genital operculum.

Legs I – IV covered in setae; tarsal area and calcaneus densely covered in setae. Trochanter I with a small ventral tubercle. Tibia I with three proximal tubercles with setae, II – IV with sparse ventral granules. Calcaneus smaller than astragalus, ≥ 7 × smaller in legs I, 9 × (II), 8 × (III), and 11 × (IV). Tarsal count: 3–7 – 4 – 4.

Penis (Figs 21 , 22 ). Pars distalis has a ventral plate with a notch that divides the plate into two halves, each with six long ventral macrosetae and one dorsal macroseta, a capsula externa shorter than the capsula interna, divided into two halves, and a finger-like apical region.

Female. Similar to male, with shorter pedipalpal femora and reduced genital operculum.

Female measurements. Total length 2.67, carapace length 0.80, dorsal scutum length 1.65, carapace max. width 1.25, mesotergum max. width 1.74. Appendage measurements: Pedipalps. Trochanter length 0.13, femora length 0.78, patella length 0.45, tibia length 0.56, tarsus length 0.53. Leg I: trochanter (tr) 0.19, femora (fe) 0.83, patella (pa) 0.35, tibia (ti) 0.66, metatarsus (mt) 0.80, tarsus (ta) 0.48. II: tr 0.27, fe 1.26, pa 0.43, ti 1.03, mt 1.45, ta 0.86. III: tr 0.23, fe 0.96, pa 0.38, ti 0.82, mt 1.15, ta 0.52. IV: tr 0.24, fe 1.29, pa 0.42, ti 1.04, mt 1.56, ta 0.64.

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 17. Fresiax mauryi 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: 1 mm. Species of Clade A, see Fig. 3.

Figure 18. Fresiax mauryi 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 19. Fresiax mauryi sp. nov. chelicerae: mesal A ectal B pedipalps: mesal C ectal D. Scale bars: 200 µm (A, B); 500 µm (C, D).

Figure 20. Fresiax mauryi sp. nov. legs I A II B III C IV D. Scale bars: 500 µm.

Figure 21. Fresiax mauryi sp. nov. penis: ventral A, B apical C, D lateral E, G dorsal H, I. Scale bars: 500 µm (A, E); 100 µm (C); 20 µm (D, H); 50 µm (B, F, G).

Figure 22. Fresiax mauryi sp. nov. penis: ventral A apical B lateral C dorsal D. Colors: ventral plate (yellow), capsula externa (blue), capsula interna (red). Scale bars: 50 µm (A); 100 µm (B, C); 500 µm (D).