Characterization of Opsin Gene Alleles Affecting Color Vision in a Wild Population of Titi Monkeys (Callicebus brunneus)

The color vision of most platyrrhine primates is determined by alleles at the polymorphic X-linked locus coding for the opsin responsible for the middle- to long-wavelength (M/L) cone photopigment. Females who are heterozygous at the locus have trichromatic vision, whereas homozygous females and all males are dichromatic. This study characterized the opsin alleles in a wild population of the socially monogamous platyrrhine monkey Callicebus brunneus (the brown titi monkey), a primate that an earlier study suggests may possess an unusual number of alleles at this locus and thus may be a subject of special interest in the study of primate color vision. Direct sequencing of regions of the M/L opsin gene using feces-, blood-, and saliva-derived DNA obtained from 14 individuals yielded evidence for the presence of three functionally distinct alleles, corresponding to the most common M/L photopigment variants inferred from a physiological study of cone spectral sensitivity in captive Callicebus. Am. J. Primatol. 73:189-196, 2011. (C) 2010 Wiley-Liss, Inc.

A new species of Callicebus Thomas, 1903 (Primates, Pitheciidae) from the states of Mato Grosso and Pará, Brazil

A new species of titi monkey, genus Callicebus Thomas, 1903, is described based on four individuals, one from a small tributary of the left bank of Rio Teles Pires, northern state of Mato Grosso, and three others from Largo do Souza, Rio Iriri, Pará, Brazil. The new species belongs to the Callicebus moloch species group, and the main diagnostic characteristics of the new species are the whitish forehead, sideburns and beard coloration, which are contiguous, forming a frame around the blackish face; overall body pelage coloration is pale grayish-brown agouti; hands, feet and tip of the tail whitish; belly and inner sides of fore and hind limbs uniformly orange. The pattern of pelage coloration and qualitative and quantitative skull morphology are described and compared to the other species of the Callicebus moloch group. Species of the Callicebus moloch group show great similarity in skull morphology and morphometrics, making the external morphological characters, specially the chromatic fields, the most reliable diagnostic trait to identify the species.