Mistralia ramirezi, 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

Mistralia ramirezi sp. nov.

Figs 35 , 36 , 37

Material examined.

Holotype. ♂ Chile. Malleco: Monumento Natural Contulmo , 38.01314 ° S, 73.18648 ° W, M. Ramírez, F. Labarque coll. 10. II. 2005 ( MNHNCL).

Etymology.

Patronym in honor to Argentine arachnologist, Martín Ramírez, esteemed colleague and friend, for his contributions to the field of spider taxonomy and systematics.

Diagnosis.

This species can be easily distinguished from the other species in the genus by having sharp tubercles on the surface of the dorsal scute and by its unique genitalia, with a U-shaped capsula externa in dorsal view.

Distribution.

Chile: Bío-Bío Region (Fig. 4 B ).

Description of male.

Measurements: Total length 3.29, carapace length 0.77, dorsal scutum length 2.22, carapace max. width 1.72. Appendage measurements: Pedipalps. Trochanter length 0.28, femora length 1.27, patella length 0.64, tibia length 1.05, tarsus length 0.95. Leg I: trochanter (tr) 0.37, femora (fe) 0.30, patella (pa) 1.13, tibia (ti) 0.58, metatarsus (mt) 0.92, tarsus (ta) 1.03. II: tr 0.76, fe 0.34, pa 1.71, ti 0.63, mt 1.47, ta 1.75. III: tr 1.55, fe 0.36, pa 1.17, ti 0.51, mt 1.13, ta 1.44. IV: tr 0.97, fe 0.41, pa 1.56, ti 0.71, mt 1.47, ta 1.98.

Dorsum (Fig. 35 ). Eta (η) hourglass-shaped dorsal scutum. Ocularium elevated, with apophysis between eyes. Carapace smooth; mesotergum with areas delimited by tubercles. Areas I – IV characterized by two setiferous tubercles: posterior margin with a row of ca. 10 setiferous tubercles. Free tergites bear a row of setiferous tubercles, similar to those found on the posterior margin of the dorsal scutum.

Chelicerae. Segment II with two prominent tubercles and few granules.

Pedipalps. Femora and tibia covered with granules when viewed from dorsal and ectal perspectives. Femora with a row of three distinct ventral and dorsal spines. Patella with two mesal tubercles and one ectal tubercle, each accompanied by subdistal setae. In ventral view, tibia with four ectal and mesal spines with subdistal setae, as well as with a row of setiferous granules. Tarsus characterized by three mesal and ectal spines covered with subdistal setae.

Legs (Fig. 35 D ). Ventral surface: I – IV with small setiferous tubercles. Sternum arrow-shaped.

Penis (Figs 36 , 37 ). Pars distalis with a ventral plate divided into two lamellae by a small cleft. Each lamella on the ventral surface bears three tiny macrosetae, while the dorsal surface has one macroseta. Capsula externa with a U-shaped slit, shorter in length compared to the capsula interna, which is tubular in shape.

Female. Unknown.

Figures

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 35. Mistralia ramirezi. sp. nov. habitus, male A dorsal view B lateral view C ventral view D leg I E pedipalp ectal F pedipalp mesal. Scale bars: 1 mm (A – D); 500 µm (E, F).

Figure 36. Mistralia ramirezi sp. nov. Penis ventral A lateral B dorsal C. Capsula interna (CI), Capsula externa (CE), dorsolateral plate (DL), ventral plate (VP), muscle (MU). Scale bar: 100 µm.

Figure 37. Mistralia ramirezi sp. nov. Penis ventral A lateral B dorsal C capsula interna (red), Capsula externa (blue), dorsolateral plate (brown), ventral plate (green). Scale bar: 100 µm.