Ami caxiuana Pérez-Miles, Miglio & Bonaldo, 2008

Pérez-Miles, Fernando, Gabriel, Ray, Miglio, Laura, Bonaldo, Alexandre, Gallon, Richard, Jimenez, Juan Jacobo & Bertani, Rogerio, 2008, Ami, a new Theraphosid genus from Central and South America, with the description of six new species (Araneae: Mygalomorphae), Zootaxa 1915, pp. 54-68 : 57-58

Ami caxiuana Pérez-Miles, Miglio & Bonaldo , sp. nov.

( Figs 4–10 ; Tables 1–2 )

Types: Holotype male, Caxiuanã [1º46’56”S, 51º27’31”W] Melgaço, Pará Brasil, 22 Oct 2003 (J.A.P. Barreiros & L.T. Miglio), MPEG 0 0 994. Paratype female, same data as holotype but 26 May 2003 (J.A.P. Barreiros & C.O. Araújo), MPEG 0 0 989.

Etymology: The specific epithet is a noun in apposition from the Tupí language for the name of the type locality, which means ‘place of many snakes’.

Diagnosis: Differs from other species by the morphology of the male palpal organ, with the main axis of the terminal embolic region directed laterally ( Figs 7–8 ), and in the female by the spermathecae, with a notched semicircular back-plate ( Fig. 9 ). This species seems to be the sister group of all other species of Ami (see Cladistics).

Description: Male (holotype): Total length, excluding chelicerae and spinnerets, 20.9. Carapace length 10.3, width 9.5. Anterior eye row slightly procurved, posterior slightly recurved. Eyes sizes and interspaces: AME 0.38, ALE 0.50, PME 0.32, PLE 0.36, AME–AME 0.24, AME–ALE 0.08, PME–PME 0.74, PME–PLE 0.04, ALE–PLE 0.20, OQ length 0.8, width 1.7, clypeus 0.4. Fovea slightly procurved, width 1.1. Labium length 1.0, width 1.7 with 23 cuspules, maxillae with ca. 38 cuspules on inner third. Sternum length 4.2. Chelicerae with 11 teeth on promargin and 11 small teeth on proximal retromargin. Tarsi I–IV densely scopulated: entire on I–II, divided in apical half of III, and divided by strip of longer, thicker setae on IV. Metatarsi I and II scopulate for distal half, III apically scopulate, IV ascopulate. Palpal tibia with two distal conical processes on retrolateral surface ( Fig. 4 ). Tibia I with paired distal proventral apophyses ( Fig. 10 ). Flexion of metatarsus I retrolateral with respect to tibial apophyses. Palpal organ piriform ( Figs 4–5 ). Spination: femora and patellae I–IV and palp, 0. Tibiae: palp 2V; I 0; II 2V; III 3V, 2P; IV 3V, 1P, 1R. Metatarsi: I 0; II 2V; III 2V, 2P; IV 5V, 2P, 2R; Tarsi I–IV and palp 0. Color: cephalothorax and legs reddish-brown; abdomen dark brown.

Female (paratype): Total length, excluding chelicerae and spinnerets, 18.7. Carapace length 7.9, width 7.2. Anterior eye row straight to slightly procurved, posterior row slightly recurved. Eye sizes and interspaces: AME 0.34, ALE 0.44, PME 0.30, PLE 0.30, AME–AME 0.16, AME–ALE 0.08, PME–PME 0.62, PME–PLE 0.04, ALE–PLE 0.14, OQ length 0.68, width 1.44, clypeus 0.13. Fovea slightly procurved, width 0.80. Labium length 0.9, width 1.2, with 26 cuspules, with ca. 46 cuspules on inner third. Sternum length 3.4. Chelicerae with 11 teeth on promargin and 11 small teeth on proximal retromargin. Tarsi densely scopulate: entire on I–II, divided by strip of longer, thicker setae on III, IV. Metatarsi I and II scopulate for distal half, III apically scopulate, IV ascopulate. Spination: femora I–IV and palp, 0. Tibiae I–IV and palp, I 2V; II 1V; III 4V, 1P; IV 3V, 1R; palp 3V, 1P. Metatarsi: I 1V; II 4V; III 4V, 2P, 2R; IV 8V, 1P, 2R, 2D. Tarsi I–IV and palp, 0. Color: cephalothorax and legs light reddish-brown, abdomen light-brown. Modified Type I urticating hairs with area b longer than usual. Spermathecae with paired ventral receptacles attached to almost discrete, notched, semicircular, sclerotized back-plate ( Fig. 9 ).

Natural history: Both specimens were taken in the same site of Terra Firme (Dry land) Forest, in pitfall traps used for a herpetological survey. The female was collected in May during the rainy season (January– June) and the male in October during the dry season (July–December).

Figures

FIGURES 1 – 16. Ami species. 1 – 4. Left palpal tibiae, males, dorsal view, showing two retrolateral processes. 1. Ami obscura; 2. Ami bladesi; 3. Ami yupanqui; 4. Ami caxiuana. 5 – 6. Ami caxiuana, dorsal view. 5. Male; 6. Female. 7 – 8. Left palpal organ, A. caxiuana, male. 7. Prolateral view, showing keels and granular area; 8. Retrolateral view. 9. A. caxiuana, spermathecae, ventral view. 10. A. caxiuana, left tibial apophyses, male, proventral view. 11 – 13. A. yupanquii, male, left palpal organ. 11. Prolateral view showing ventral flattened area (on left); 12. Retrolateral view; 13. Dorsal view. 14. A. yupanquii, male, left tibial apophyses, proventral view. 15. A. yupanquii, spermathecae, ventral view. 16. A. bladesi, male, left tibial apophyses, proventral view.