Morphologic, karyotypic, and molecular evidence of a new form of Chiropotes (primates, pitheciinae).

Morphologic, karyotypic, and molecular analyses were carried out in 25 specimens of a distinct morph of Chiropotes (henceforth termed Chiropotes sp.) obtained from a number of localities in the Brazilian Amazon. Pelage coloration clearly distinguishes the collected specimens and all other known species of this genus. A distinct karyotype was described for Chiropotes sp. It differs from C. satanas chiropotes by two pericentric inversions, and from C. satanas utahicki by three, which suggests that these taxa are reproductively isolated. Morphometric analyses did not show significant differentiation between these Chiropotes taxa. Molecular analyses confirmed the monophyly of the subfamily Pitheciinae and genera Chiropotes, Cacajao, and Pithecia (the latter appearing as the most basal lineage of the pithecine clade). The genetic distances between C. s. utahicki and Chiropotes sp. from Rio Negro were greater than those between three recognized species of Pithecia, but smaller than those between Cacajao calvus and Cacajao melanocephalus. The most appropriate name for Chiropotes sp. from Rio Negro is C. israelita. This species, C. s. chiropotes, and C. s. utahicki are allopatric. Pelage coloration, karyotype, and molecular analysis strongly indicate that C. chiropotes, C. utahicki, and Chiropotes israelita deserve species status.