Genetic analysis of an insular population of Sapajus nigritus (Primates: Cebidae) in Rio de Janeiro state, Brazil

Abstract

The black-horned capuchin (Sapajus nigritus) is a neotropical primate with wide distribution from southeastern Brazil to northeastern Argentina. Although this species has been described with coat pattern variation, even with intrapopulational differences, and characterized as having the greatest genetic diversity among Sapajus species, there are still few studies on natural populations that contribute to the knowledge of this intraspecific variability. We examined individuals from an as yet unstudied population of Ilha da Marambaia, Rio de Janeiro (RJ) state, Brazil, compared with published data for S. nigritus. We sought to confirm the species through phenotypic and genetic characterization using C-banding and fluorescence in situ hybridization with #11qHe+/21WCP probes for chromosomal constitutive heterochromatin (He+) patterns, and cytochrome c oxidase I and II gene sequences for phylogenetic analysis. The coat presented two color patterns, varying from brown to blackish on the body, yellow to brown on the chest, and white to yellow on the face, besides the presence and shape of the tufts on the head, corresponding to S. nigritus. He+ was identified in pairs 4, 12, 13 and 17, and less consistently in pairs 6, 19 and 21, already described for this species. While most Sapajus species have a large He+ block, here pair 11 was identified without extracentromeric He+, the same as reported for S. nigritus from Argentina. Molecular analysis showed divergence of this population from other S. nigritus sequences, reinforcing a trend already demonstrated when samples from RJ are compared with the rest of the distribution, which may represent an evolutionary deviation.

Phylogeography, genetic diversity, and intraspecific genetic structure of the black‐horned capuchin (Sapajus nigritus)

“…The split of northern populations within S. nigritus preceded the diversification of most capuchin species and led to the divergence of the northern clade from other capuchins at 1.56 Ma ago. This clade is represented by populations RIO and TER of our sampling and by Angra dos Reis (Lynch Alfaro,Boubli, et al, 2012) and Ilha da Marambaia(Penedo et al, 2021). Vicariance events are known to have had an important role in the diversification of Neotropical primates(Jameson Kiesling et al, 2015).…”

“…Up to now the genetic structure of S. nigritus is mostly unknown. While some studies have addressed genetic diversity in isolated or captive populations (Nieves et al, 2021; Penedo et al, 2021; Tokuda et al, 2018), others have included more localities but assessed genetics of only one or a few individuals per locality or species (Lima et al, 2017; Lynch Alfaro, Boubli, et al, 2012). In this context, here we sequence and analyze data from three mitochondrial genetic markers from populations sampled across much of the distribution of S. nigritus to have a better understanding of evolutionary history, intraspecific population structure, and genetic diversity, to build a genetic‐geographic database as a tool to aid in S. nigritus release into appropriate locations in the wild, and more broadly, to inform better management decisions for wild and captive black‐horned capuchins.…”