Type material. ³ holotype: BRAZIL:Pará: Portel, Rio Camarapi, Igarapé Mirituba, 02°07’23.80”S, 50°37’39.90”W, 30.XI–4.XII.2015, leg. R. Saturnino et al. (pitfall trap) (MPEG. ARA 36739).
Paratypes: BRAZIL:Pará: Portel, Comunidade Pacoval, 01°50’10.80”S, 50°38’27.80”W, 1. VI.2016, leg. D.D. R. Guimarães (beating tray), 1³ (MPEG. ARA 36740); Rio Camarapi, Igarapé Banã, 02°03’21.30”S, 50°42’21.60”W, 24– 27.I.2016, leg. R. Saturnino et al. (pitfall trap), 1³ (MPEG. ARA 36741).
Etymology. The specific name is a noun in apposition and refers to the Camarapi River, a watercourse that runs through the type locality.
Diagnosis. Males of Trachelopachys camarapisp. nov. resemble those of T. keyserlingi (Roewer, 1951), T. gracilis (Keyserling, 1891) and T. singularis (Caporiacco, 1955) by the massive, slightly bifid retrolateral tibial apophysis and narrow and membranous conductor (Figs 1C, D; Platnick 1975: figs 34, 35, 38, 39, 54, 55), differing by the wider embolus with a bifid tip (Fig. 1C); females are similar to those of T. singularis by the continuous and arched anterior margin of the median atrium (Fig. 1E; Platnick 1975: fig. 56), but differ by the gradual curvature of the posterior part of the spermatheca (Fig. 1F). Females further differ from those of all other congeners by the anterior part of the spermathecae resting anteriorly to the anterior margin of the atrium (Figs 1E, F).
Description. Male holotype. Carapace reddish-brown, punctuated, with many small reclined and erect white setae; cephalic elevation weak. Chelicerae reddish-brown, with 3 promarginal and 2 retromarginal teeth. Endites orange, labium brown. Sternum orange. Legs yellow, with many thin erect setae. Abdomen gray. Total length 3.48. Carapace 1.65 long, 1.34 wide, 0.66 high. Eye sizes and interdistances: AME 0.11, ALE 0.10, PME 0.11, PLE 0.10, AME̅AME 0.08, AME̅ALE 0.03, PME̅PME 0.11, PME̅PLE 0.10. Clypeus 0.12 high. Chelicera 0.58 high, 0.37 wide. Sternum 0.86 long, 0.73 wide. Labium 0.29 long, 0.26 wide. Endite 0.37 long, 1.42 wide. Legs: leg I 4.43 total length (femur 0.59, patella 1.16, tibia 0.84, metatarsus 0.57, tarsus 1.27); leg II 4.04 (0.54, 1.07, 0.85, 0.62, 0.96); leg III 3.72 (0.46, 0.71, 0.76, 0.46, 1.33); leg IV 5.18 (0.50, 1.18, 1.20, 0.54, 1.76). Palp: cymbium piriform; bulb longer than wide; embolus wide, wider than proximal portion of sperm duct, with indistinct base and bifid tip, slightly inclined retrolaterally, with semispiral projection on retrolateral face, in basal half; conductor hyaline, thin, with wide base, ventral to embolus; tibia about 2/5 of cymbium length; RTA about half length of tibia, with wide sclerotized dorsal branch in retrolateral view.
Female paratype (MPEG. ARA 36740). Carapace and chelicerae as in male. Endites, labium and sternum gray. Legs and abdomen as in male. Total length 3.27. Carapace 1.64 long, 1.37 wide, 0.52 high. Eye sizes and interdistances: AME 0.13, ALE 0.11, PME 0.11, PLE 0.10, AME̅AME 0.08, AME̅ALE 0.03, PME̅PME 0.14, PME̅PLE 0.12. Clypeus 0.12 high. Chelicera 0.61 high, 0.34 wide. Sternum 0.78 long, 0.86 wide. Labium 0.32 long, 0.30 wide. Endite 0.42 long, 1.22 wide. Legs: leg I 4.32 total length (femur 0.58, patella 1.07, tibia 0.80, metatarsus 0.70, tarsus 1.17); leg II 3.79 (0.54, 0.94, 0.79, 0.59, 0.93); leg III 3.76 (0.45, 0.69, 0.75, 0.50, 1.37); leg IV 5.14 (0.51, 1.18, 1.23, 0.59, 1.63). Epigyne: atrium oval, longer than wide, anterior edge wider; copulatory openings wide, located in anterior part of atrium, spaced by more than their width; spermathecae S-shaped, about 6 times longer than wide, anterior part wider than posterior, spaced by one diameter posteriorly, by more than one diameter anteriorly; basal lobes inserted ventrally in posterior part of spermathecae; copulatory ducts as wide as anterior part of spermathecae, short, about half length of spermathecae.
Natural history.T. camarapisp. nov. represents the first record of the genus for the Amazon, where the climate is equatorial, always hot and wet, and different from the localities where the other species were collected. However, the occurrence of this species in a savanna environment (Figs 2A, B) may indicate a preference for drier habitats.
Distribution. Known only from Pará, Brazil (Fig. 2C).