Allpamayu suyuwixsa Nelson, Juan, Chaparro, Ochoa, Allen & West, 2026, n. sp.

Matías Beratz Nelson; Nelson Ferretti Juan; Juan C. Chaparro; Jose Antonio Ochoa; Joshua P. Allen; Rick C. West · (2026) · DOI: 10.5281/zenodo.19608241

Resumen

Allpamayu suyuwixsa n. sp. (Figs 2-8) urn:lsid:zoobank.org:act: A972C51B-6E45-46D7-AD80-4DBF5290ACF3 TYPE MATERIAL. — Holotype. Peru • 1♂; Cusco department, Calca province, Maska; 13°24’14.07”S, 71°50’2.37”W; 3260 m a.s.l.; 22.IV.2021; Allen J. leg.; MUBI 121. Paratypes. Peru • 1♀; Cusco department, Acomayo province, Yananpampa, Laguna Pomacanchi; 13°59’54.52”S, 71°31’18.19”W; 3757 m a.s.l.; 7.X.2023; Ferretti N., Chaparro J. West R. legs.; MUBI 194 • 3♀; Cusco department, Canchis province, Chuquicahuana; 13°59’20.60”S, 71°29’41.56”W; 3785 m a.s.l.; 7.X.2023; Ferretti N., Chaparro J. West R. legs; MUBI 193 • 1♀; Cusco department, Yananpampa, Laguna Pomacanchi; 13°59’54.52”S, 71°31’18.19”W; 3757 m. a.s.l.; 7.X.2023; Ferretti N., Chaparro J. West R. legs; MUBI 373. OTHER MATERIAL EXAMINED. — Peru • 1♂; Cusco department, Chumbivilcas province, Velille; 14°34’1”S, 71°55’16”W; 3787 m a.s.l.; 30.VIII.2023; Ccahuana R., Pumaccahua Z. legs; MUBI 160 • 1♂, 3♀; Cusco department, Inca trail to Machu picchu, near Wayruro river; 3500 m a.s.l.; 15.I.1983; Roig A. leg.; MACN-Ar 46343. ETYMOLOGY. — The specific epithet is taken from the Central Quechua language, ‘suyu’ meaning ‘striped’ and ‘wixsa’ meaning ‘abdomen’ or ‘belly’ (Parker & Ibañez 1964). DESCRIPTION Male holotype (MUBI 121) Total length 14.35. Carapace length 7.34, width 6.01. Coloration in live: Carapace and chelicerae black with bronze setae along carapace margins, around striae, and forming a dorsal line above chelicerae (Fig. 7A), legs dark grey with bronze setae on coxa and trochanter (Fig. 7A), abdomen dark grey with bronze mottling on dorsal and long setae in the proximal region, spinnerets dark grey (Fig. 7A). Coloration in alcohol: Carapace reddish-brown (Fig. 2A), darker at striae and around the ocular tubercle (Fig. 2A; G), abdomen dark brown, with short hairs and small white spots (Fig. 2 B-D). Clypeus length 0.09. Eye tubercle: length 0.77, width 0.97. Anterior eye row procurved, posterior row slightly recurved. Fovea slightly recurved (Fig. 2A), width 0.76. Labium length 0.52, width 1.01. Sternum length 3.20, width 2.76 with three pairs of visible rounded sigillae, about half of diameter separate from sternum margin (Fig. 2E). Cheliceral furrow with nine teeth on prolateral margin and 14 small denticles on the retrolateral margin. Labium with 20 cuspules (Fig. 2F). Maxilla with 92 cuspules on each side (Fig. 2G). Eye sizes and interdistances: AME 0.14, ALE 0.28, PME 0.15, PLE 0.21, AME–AME 0.17, AME–ALE 0.08, ALE– ALE 0.10, PME–PLE 0.06, PME–PME 0.41, ALE–PLE 0.10, PLE–PLE 0.61. Leg measurements: palp: femur 2.95 / patella 2.00 / tibia 2.11 /tarsus 1.17 / total 8.23. Legs I: femur 4.80 / patella 3.22 / tibia 3.53 / metatarsus 3.30 / tarsus 2.23 / total 17.08. II: 4.61 / 2.89 / 3.23 / 3.26 / 2.33 / 16.32. III: 4.38 / 2.43 / 2.90 / 4.21 / 2.38 / 16.30. IV: 5.75 / 3.03 / 4.45 / 6.41 / 2.91 / 8.23. Spines: tarsi without spines. Palp: femur 1-3-1d, patella 0, tibia 1-1-1v, 0-2-2p, 0-0-1r; Legs: I: femur 0, patella 0, tibia 2-3-1v, 0-1-0p, metatarsus 1-0-1v; II: femur 0-0-2p, patella 0, tibia 2-1-3v, 1-1-0p, metatarsus 1-0-1v, 1-0-0p; III: femur 1-1-2p, 1-1-1r, patella 0-1-0p, 0-1-0r, tibia 2-1-3(ap)v, 2-2- 0p, 1-2-0r, metatarsus 3-2-3(ap)v, 2-2-2p, 2-1-2r; IV: femur 0-1-1r, 0-2-2d, patella 0-1-0p, 0-1-0r, tibia 3-2-3v, 2-2-0p, 1-2-1r, metatarsus 1-1-3v, 4-4-1p, 3-1-3r, 0-0-2d. Tibial apophysis composed of two branches, retrolateral branch slightly larger than prolateral branch (Fig. 3 A-C). Both branches with a strong spine in the apical region (Fig. 3C). Metatarsi of the first pair of legs with a ventral tumescent area (white area) covered with scopulate hairs (Fig. 3B). Paired tarsal claws of I, II, III and IV smooth. ITC absent in all legs. Scopulae on ventral metatarsi: 3/4 of metatarsi I, II and III occupied by scopula, and IV with scopula on 1/2 of metatarsus divided by a longitudinal smooth area. Tarsal scopulae: I, II, III and IV divided by a longitudinal band of setae.Tarsi of all legs with pseudosegmentation (cracked) as a white transversal line (Fig. 3A). Clavate trichobothria on tarsi of all legs forming two parallel rows along half the length of tarsus. Palpal tibia long and slightly excavated with two long ventral spines (Fig. 4F), cymbium with a small group of apically erect long setae (Fig. 4E, F). Palpal bulb with elongated tegulum and twisted embolus (Fig. 4 A-D). Embolus long, curved on its apical half, with two parallel keels at the base of tegulum and extending towards the embolus, and a small crest present between the keels (Fig. 4A). Abdomen length 8.2, width 5.6. Spinnerets: PMS length 0.63; PLS tri-segmented, basal segment 0.81, median segment 0.49, and apical segment 0.64, digitiform in shape (Fig. 2D). Female paratype (MUBI 194) Total length 15.35. Carapace length 7.46, width 6.22. Coloration in life: Carapace light brown with golden reflections, chelicerae black, legs brown with darker femora, abdomen brown with dorsal and lateral stripes barely distinguished (Fig.7 B-D).Coloration in alcohol: Carapace reddish with short black hairs on ocular region (Fig. 5A, G), legs light brown, abdomen light brown with dark stripes more noticeable in lateral sides (Fig. 5B, C). Clypeus length 0.11. Eye tubercle: length 0.60, width 1.11. Anterior eye row slightly procurved, posterior slightly recurved (Fig. 5G). Fovea straight (Fig. 5A), width 0.59. Labium length 0.84, width 1.25. Sternum length 3.33, width 3.08, with three pairs of rounded sigillae, about half of diameter separate from sternum margin (Fig. 5E). Cheliceral furrow with 10 teeth on prolateral margin and 24 small denticles on the retrolateral margin. Labium with 22 cuspules (Fig. 5F). Maxilla with 125 cuspules on each side (Fig. 5F). Eye sizes and interdistances: AME 0.14, ALE 0.30, PME 0.18, PLE 0.24, AME–AME 0.21, AME–ALE 0.12, ALE– ALE 0.11, PME–PLE 0.10, PME–PME 0.47, ALE–PLE 0.14, PLE–PLE 0.65. Leg measurements: palp: femur 3.26 / patella 1.99 / tibia 2.12 /tarsus 1.91 / total 9.28. Legs I: femur 4.52 / patella 2.79 / tibia 3.27 / metatarsus 2.53 / tarsus 1.83 / total 14.94. II: 4.02 / 2.70 / 2.72 / 2.50 / 1.99 / 13.93. III: 3.36 / 2.34 / 2.57 / 3.43 / 2.07 / 13.77. IV: 4.90 / 2.78 / 4.00 / 4.83 / 2.34 / 18.85. Spines: tarsi without spines. Palp: femur 0-0-1p, patella 0, tibia 0-2-3(ap)v, 0-0-1(ap)p; Legs: I: femur 0-0-1p, patella 0, tibia 1-1-1(ap)v, 0-1-0p, metatarsus 1-0-1v; II: femur 0-0- 1p, patella 0, tibia 1-1-1(ap)v, 0-0-1p, metatarsus 2-0-1(ap) v; III: femur 0-1-2p, 0-0-1r, patella 0-1-0r, tibia 1-1-3(ap)v, 2-2-0p, 1-1-0r, metatarsus 2-2-3v, 1-2-1p, 2-1-2r, 2-0-2d; IV: femur 0-0-1p, patella 0, tibia 1-1-3(ap)v, 2-2-0p, 1-2-0r, metatarsus 2-2-3v, 2-1-2p, 2-1-2r, 2-0-2d. Paired tarsal claws of STC with teeth: leg I: int 6/0, ext 3/6; II: 6/0, 3/6; III: 6/0, 5/6; IV: 6/0, 5/6. ITC absent from all legs. Scopulae on ventral metatarsi: metatarsi I and II with complete scopulae, III and IV with scopula on 1/2 of metatarsus divided by a longitudinal smooth area. Tarsal scopulae: I, II, III and IV divided by a longitudinal band of setae. Tarsi of all legs integral (Fig. 6A, B). Clavate trichobothria on tarsi of legs forming two parallel rows along the half of tarsus length (Fig. 6C). Abdomen length 7.89, width 4.52. Spinnerets: PMS length 0.64; PLS tri-segmented, basal segment length 1.17, median segment 0.63, apical segment 0.82, digitiform in shape (Fig. 5C). Spermathecae with basal large oval receptacles and a short wide duct oriented laterally carrying two to three rounded lobes (Fig. 5H). DISTRIBUTION AND NATURAL HISTORY Allpamayu n. gen. is known from southeastern Peru, specifically in the Cusco department (Fig. 8A). Vegetation at the type locality consists of montane grasses, scattered low shrubs and transplanted pine or eucalyptus trees (Fig. 8B). Specimens in this study were found between 3200-3800 m a.s.l. Female and immature specimens of both sexes construct thin, loosely-webbed burrows, with no distinct entrance, located under angular stones amongst the roots of surrounding plants and grasses (Fig. 7B) in inter Andean valleys. Some females found in October carried a single white detached egg sac, measuring between 7-15 mm in diameter (Fig. 7C). Average annual temperatures in the region of Allpamayu suyuwixsa n. gen, n. sp. range from 11-14°C with the rainy season occurring between December to April and a drier cooler season between May and November. Mature males were found in the months of January, April and August. Unlike most theraphosid males that are seasonal breeders, maturing and wandering in search of receptive females for a short period generally at the onset of the rainy season, Allpamayu suyuwixsa n. gen, n. sp. males have a more varied mating season which would suggest they are opportunistic breeders, maturing and breeding whenever the conditions of their environment are favorable. CLADISTIC ANALYSIS The results of the implied weighting (IW) analyses are shown in Table 1. The strict consensus of IW resulted in a tree with 123 steps (CI = 0.5 and RI = 0.8). The tree shown in Figure 9 represents the result of the implied weighting analyses with K = 11.2, which is within the range of k-values that showed the most consistent topology and shortest length. The analysis resulted in the paraphyletic condition of the subfamily “ Ischnocolinae ” (blue and red rectangles on Fig. 9). The genus Ischnocolus Ausserer, 1871 (Ischnocolinae sensu stricto) was recovered as sister to the remaining taxa (Fig. 9). The subfamily Schismatothelinae was recovered as monophyletic (Fig. 9). The genus Holothele was not recovered as monophyletic in the analysis (Fig. 9). The new genus Allpamayu was recovered as the sister genus of a large paraphyletic group formed by the genera Holothele, Reichlingia (Rudloff, 2001), Acanthopelma Pickard-Cambridge, 1897 and a representative of the subfamily Trichopelmatinae, Trichopelma nitidum Simon, 1888 (Fig. 9).

Instituciones: Universidad Nacional de San Antonio Abad del Cusco