Nativus yasuni, Rheims & Casas, 2025

Nativus yasuni sp. nov.

Figs 1–16 View FIGURES 1–9 View FIGURES 10–15

Type material. Holotype: ECUADOR: Orellana: ♂, Orellana, Tiputini Biodiversity Station, near Yasuní National Park , Erwin Transect T/1 Sta. 1, 200–250 mts., lot 2024 ( 00º37'55"S, 76º08'39"W), 8 February 1999, T. L. Erwin et al. leg. ( USNM). GoogleMaps

Paratypes: ECUADOR: Napo: 1 ♂, Napo, Jatun Sacha Biological Station ( 01º03'57.5"S, 77º37'0.2"W). 1–5 December 2009, Oonopidae PBI Team leg. ( IBSP 306712 View Materials ) GoogleMaps . Orellana: 1 ♀, Reserva Étnica Waorani , transect ent, 1km S Onkone Gare Camp, 216.3 mts, lot 928 ( 00º39'25"S, 76º27'10.8"W), 9 October 1994, T GoogleMaps . L. Erwin et al. leg. ( USNM) ; 1 ♀, same collection data as for previous specimen, lot 1953 ( USNM) . PERU: Loreto: 1 ♂, Maynas, Rio Shino , 212 mts. ( 01º16'58.58"S, 75º16'25'21"W), 28 December 2008, R. Yawarcani leg. ( MUSM) ; 1 ♀, same collection data as for previous specimen ( MUSM); [Maynas], Rio Napo , 206 mts. ( 01º42'9.44"S, 74º47'9.03"W), 3 November 2008, R. Yawarcani leg. ( MUSM) GoogleMaps .

Additional material examined. PERU: Loreto: 1 ♂, 2 ♀, Maynas, Rio Shino , 200 mts. ( 01º17'0.43"S, 75º15'14.99"W, 28 December 2012, R. Yawarcani leg. ( MUSM) GoogleMaps ; 1 ♀, same collection locality as for previous specimen, 95 mts. ( 01º12'33.8"S, 75º22'32"W), 3 January 2009, R. Yawarcani leg. ( MUSM) GoogleMaps ; 2 ♀, [Maynas], Rio Napo , 206 mts. ( 01º42'9.44"S, 74º47'9.03"W), 3 November 2008, R. Yawarcani leg. ( MUSM) GoogleMaps ; 1 ♀, [Maynas], Rio Nashano , 195 mts. ( 01º12'33.8"S, 75º22'32"W), 3 January 2009, R. Yawarcani leg. ( MUSM) GoogleMaps .

Etymology. The specific name refers to the Yasuní National Park in Ecuador, one of the localities in which the species has been found, noun in apposition.

Diagnosis. Males of N. yasuni sp. nov. resemble those of N. carare Casas & Rheims, 2023 (figs 16–18), N. mariua Casas & Rheims, 2023 (figs 59–61) and N. tawu Casas & Rheims, 2023 (figs 106–108) by the palps with embolus roughly straight and tegulum lacking a retrodistal tegular protrusion (RdP). They are distinguished from these species by the dorsal branch of RTA (dRTA) being hook-shaped and subdistal ( Figs 7 View FIGURES 1–9 , 12 View FIGURES 10–15 ) (vs. more distally located in the other species, spade-shaped in N. carare , and bifid in N. mariua and N. tawu ) and by the presence of a laminar and curved tegular projection close to the hyaline projection at the base of the embolus ( Figs 5–7 View FIGURES 1–9 , 10–12 View FIGURES 10–15 ) (vs. absent in N. carare , and small and triangular in N. mariua and N. tawu ). Females differ from all congeners by the epigyne with lateral lobes touching each other medially ( Figs 8 View FIGURES 1–9 , 13 View FIGURES 10–15 ) (vs. fused medially or slightly posteriorly in all other species) and vulva with first winding laterad and then curved and encapsulated in a rounded structure ( Figs 9 View FIGURES 1–9 , 14–15 View FIGURES 10–15 ) (vs. first winding antero-laterad and then strongly convoluted, encapsulated within a sclerotized, elongated structure in the other species).

Description. Male ( Holotype): Prosoma brown, with slightly darker margins, short longitudinal marks extending posteriorly from behind eyes and radiating thoracic striae slightly darker than carapace; fovea very slightly conspicuous, dark brown; eye borders black; legs, chelicerae and pedipalps brown, lighter than prosoma; labium yellowish cream-colored with orange brown base; sternum yellowish cream-colored with slightly darker margins; opisthosoma cream-colored ( Figs 1–2 View FIGURES 1–9 ). Total length 6.1. Prosoma: 2.8 long, 2.8 wide. Opisthosoma: 2.9 long, 1.9 wide. Eyes: diameters: 0.16, 0.22, 0.19, 0.26; interdistances: 0.09, 0.03, 0.21, 0.23, 0.20, 0.19. Legs (2143): I: 19.1 (4.6, 2.1, 5.1, 4.9, 2.4); II 21.8 (5.4, 1.4, 6.1, 6.2, 2.7); III: 13.6 (3.8, 1.0, 3.5, 3.8, 1.5): IV: 17.2 (4.6, 1.0, 4.1, 5.3, 2.2). Palp: ventral tibial apophysis (VTA) absent; ventral branch of RTA (vRTA) slightly over two times longer than wide in retrolateral view; projection close to the embolus base (bp) laminar, two times longer than wide, apically rounded; dorsal tegular apophysis (DTA) sickleshaped; embolus short and straight, with wide base, with tip reaching slightly more than half conductor length ( Figs 5–7 View FIGURES 1–9 , 10–12 View FIGURES 10–15 ).

Female ( Paratype, lot 928): Coloration pattern as in male, but darker overall ( Figs 3–4 View FIGURES 1–9 ). Total length 5.8. Prosoma: 2.7 long, 2.7 wide. Opisthosoma: 3.0 long, 1.9 wide. Eyes: diameters: 0.15, 0.25, 0.17, 0.26; interdistances: 0.08, 0.03, 0.20, 0.25, 0.20, 0.20. Legs (2413): I: 11.5 (3.2, 1.2, 3.1, 2.7, 1.3); II: 13.1 (4.0, 1.2, 3.5, 3.1, 1.3); III: 9.9 (2.9, 1.0, 2.4, 2.5, 1.0); IV: 11.6 (3.2, 0.9, 2.8, 3.3, 1.4). Epigyne: epigynal field slightly longer than wide; with lateral lobe (LL) with curved lateral margins, touching each other medially throughout a third of their length; pair of elongated copulatory depressions bearing copulatory openings posteriorly ( Figs 8 View FIGURES 1–9 , 13 View FIGURES 10–15 ). Vulva: internal duct system with first winding strongly sclerotized, with rugged margins, curving into rounded structure; fertilization ducts antero-laterad ( Figs 9 View FIGURES 1–9 , 14–15 View FIGURES 10–15 ).

Variation. Males (n=5): total length 5.3–6.1; prosoma length 2.51–2.9; femur I length 4.2–4.7. Females (n=9): total length 4.87–7.0; prosoma length 2.41–3.15; femur I length 3.1–3.66.

Distribution. Known from the Amazonian region of Ecuador, in the vicinities of Yasuní National Park, in the provinces of Orellana and Napo, and from northern Peru, at Maynas province, Loreto department ( Fig. 16).