Nerudiella choapa, 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

Nerudiella choapa sp. nov.

Figs 92 , 93 , 94 , 95 , 96 , 97

Material examined.

Holotype. ♂ Chile. Valparaíso: Pichicuy, Quebrada Huaquén , E. Maury coll., 25. X. 1988 ( MNHNCL) . Paratypes. Chile. Coquimbo (Choapa province): Pichidangui, Cerro La Silla del Gobernador , E. Maury coll., 31. X. 1988, 3 ♂ ( MACN) . Same data 6 ♀ 2 imm. ( MACN) .

Etymology.

The specific epithet “ choapa ” is derived from one of the locality where the species was collected, the Choapa province in the Coquimbo region of Chile. It is used as noun in apposition to indicate the association of the species with this specific geographic location.

Diagnosis.

This species can be distinguished from its congeners by several key characteristics. Firstly, its dorsal surface and pedipalps are densely setose. Additionally, the femora and tibia of the pedipalp are covered with small tubercles. The unique male genitalia has a capsula externa that covers the dorsal and lateral surfaces. The apical region of the capsula externa is bent at a 90 - degree angle in relation to the axis of the genitalia, and there are two small parallel apical structures present. This species shares similarities with Nerudiella zapallar sp. nov., particularly in the apical region of the capsula externa, although it is relatively shorter in comparison in the latter species.

Distribution.

Chile: Coquimbo and Valparaíso Regions (Fig. 4 F ).

Description of male holotype.

Measurements: Total length 2.19, carapace length 0.94, dorsal scutum length 1.77, carapace max. width 1.33, dorsal scutum max. width 1.77. Appendage measurements: Pedipalps. Trochanter length 0.21, femora length 0.90, patella length 0.49, tibia length 0.70, tarsus length 0.86. Leg I: trochanter (tr) 0.21, femora (fe) 0.86, patella (pa) 0.45, tibia (ti) 0.67, metatarsus (mt) 0.82, tarsus (ta) 0.61. II: tr 0.20, fe 1.21, pa 0.53, ti 0.97, mt 1.07, ta 1.23. III: tr 0.24, fe 0.83, pa 0.39, ti 0.68, mt 0.77, tr 0.64. IV: tr 0.24, fe 1.19, pa 0.57, ti 0.96, mt 1.13, ta 0.75.

Dorsum (Fig. 92 , 93 ). Eta (η) hourglass-shaped dorsal scutum. Ocularium low and rounded, with small tubercles. Dorsal scutum and free tergites with microgranulation. Mesotergal areas lack clear separation but are covered with small setiferous tubercles.

Chelicerae (Fig. 94 A, B ). Segment I with a sharp tubercle on the dorso-distal surface, with two proximal tubercles. In segment II, there are scattered setae visible in both the ectal and ventral views. In the front view, there is a prominent triangular tubercle that stands out from the others.

Pedipalps (Fig. 94 C, D ). Trochanter with two small dorsal tubercles and one ventral tubercle. Femora with a dorso-mesal area with setiferous tubercles, including two stronger ones in the proximal region. In the ventral view, there are three prominent proximal spines and a row of small tubercles. Patella with a mesal setiferous tubercle. Tibia with three ventral-ectal spines and two ventral-mesal spines, with the lateral and dorsal areas with small setiferous tubercles. Tarsus with three mesal and ectal spines with subdistal setae, as well as additional setae and a few setae.

Legs (Fig. 95 ). Coxa I with 11–13 setiferous tubercles, the two apical ones being stronger and more prominent than the others. Coxa II with 18–20 setiferous tubercles, while coxa IV has 5–6 small tubercles. Bridges between legs do not obstruct the spiracles. The smooth surface occupies ~ 1 / 3 of leg II, ¾ of leg III, and <1 / 3 of leg IV. Within smooth area of leg II, there are two small tubercles with subdistal setae on each side. Sternum arrow-shaped. Legs covered in small tubercles, and the astragalus is longer than the calcaneus on all legs (Fig. 95 ). Tarsal count: 3–5 – 4 – 4.

Penis (Figs 96 , 97 ). Genitalia: Pars distalis with a ventral plate bearing a cleft that divides the plate into two lamellae. Each lamella has three pointed macrosetae on the ventral surface and one macroseta on the dorsal surface; capsula externa covering the dorsal and lateral surface, having the apical region bent at an angle of 90 ° in relation to the axis of the genitalia. It includes a pair of small apical processes in the form of small “ wings ”. The capsula interna also has a pair of lateral processes, which are long and ventrally sloping. Capsula interna longer than capsula externa, with its apical portion thinner.

Female. Similar to males, with shorter pedipalpal femora.

Female measurements. Total length 2.63, carapace length 1.0, dorsal scutum length 2.11, carapace max. width 1.47, mesotergum max. width 2.07. Appendage measurements: Pedipalps. Trochanter length 0.27, femora length 0.84, patella length 0.52, tibia length 0.61, tarsus length 0.92. Leg I: trochanter (tr) 0.28, femora (fe) 0.88, patella (pa) 0.48, tibia (ti) 0.68, metatarsus (mt) 0.84, tarsus (ta) 0.63. II: tr 0.29, fe 1.16, pa 0.56, ti 0.89, mt 1.05, ta 1.20. III: tr 0.28, fe 0.81, pa 0.38, ti 0.64, mt 0.84, ta 0.67, IV: tr 0.29, fe 1.18, pa 0.61, ti 0.98, mt 1.25, ta 0.75. Tarsal count 3–6 – 4 – 4.

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 92. Nerudiella choapa sp. nov. habitus, male A dorsal view B lateral view C ventral view. Scale bars: 1 mm.

Figure 93. Nerudiella choapa sp. nov. male, SEM images of habitus A dorsal view B lateral view C, D ventral view. Scale bars: 1 mm (A, B, C); 500 µm (D).

Figure 94. Nerudiella choapa sp. nov. chelicerae: mesal A ectal B pedipalps: mesal C ectal D. Scale bars: 200 µm (A, B); 500 µm (C, D).

Figure 95. Nerudiella choapa sp. nov. legs I A II B III C IV D. Scale bars: 500 µm (A, B, D); 200 µm (C).

Figure 96. Nerudiella choapa sp. nov. penis: ventral A, B apical C lateral D, E dorsal F, G. Scale bars: 200 µm (A, D, F); 50 µm (B, C); 100 µm (E, G).

Figure 97. Nerudiella choapa 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, B); 100 µm (C); 200 µm (D).