Revalidation of Mazama rufa (Illiger 1815) (Artiodactyla: Cervidae) as a Distinct Species out of the Complex Mazama americana (Erxleben 1777)

Abstract

The red brocket deer Mazama americana Erxleben, 1777 is considered a polyphyletic complex of cryptic species with wide chromosomal divergence. Evidence indicates that the observed chromosomal divergences result in reproductive isolation. The description of a neotype for M. americana allowed its genetic characterization and represented a comparative basis to resolve the taxonomic uncertainties of the group. Thus, we designated a neotype for the synonym Mazama rufa Illiger, 1815 and tested its recognition as a distinct species from the M. americana complex with the analysis of morphological, cytogenetic and molecular data. We also evaluated its distribution by sampling fecal DNA in the wild. Morphological data from craniometry and body biometry indicated an overlap of quantitative measurements between M. rufa and the entire M. americana complex. The phylogenetic hypothesis obtained through mtDNA confirmed the reciprocal monophyly relationship between M. americana and M. rufa, and both were identified as distinct molecular operational taxonomic units by the General Mixed Yule Coalescent species delimitation analysis. Finally, classic cytogenetic data and fluorescence in situ hybridization with whole chromosome painting probes showed M. rufa with a karyotype of 2n = 52, FN = 56. Comparative analysis indicate that at least fifteen rearrangements separate M. rufa and M. americana (sensu stricto) karyotypes, which confirmed their substantial chromosomal divergence. This divergence should represent an important reproductive barrier and allow its characterization as a distinct and valid species. Genetic analysis of fecal samples demonstrated a wide distribution of M. rufa in the South American continent through the Atlantic Forest, Cerrado and south region of Amazon. Thus, we conclude for the revalidation of M. rufa as a distinct species under the concept of biological isolation, with its karyotype as the main diagnostic character. The present work serves as a basis for the taxonomic review of the M. americana complex, which should be mainly based on cytogenetic characterization and directed towards a better sampling of the Amazon region, the evaluation of available names in the species synonymy and a multi-locus phylogenetic analysis.

Cytogenetic Mapping of Cattle BAC Probes for the Hypothetical Ancestral Karyotype of the Family Cervidae

“…The most surprising examples of rapid and radical karyotypic evolution are found in the genera Muntiacus and Mazama of forest deer [Duarte et al, 2008;Abril et al, 2010;Mudd et al, 2020]. These genera demonstrate great variation in chromosome number (from 2n = 6 to 2n = 46 for Muntiacus and from 2n = 32 to 2n = 70 for Mazama) in closely related and morphologically similar species, which has led to reports of complexes of cryptic species associated with intraspecific chromosome polymorphisms, and discovery of new species in recent decades [Yang et al, 1995[Yang et al, , 1997aDuarte and Jorge, 2003;Abril and Duarte, 2008;Abril et al, 2010;Fiorillo et al, 2013;Valeri et al, 2018;Cifuentes-Rincón et al, 2020;Galindo et al, 2021;Peres et al, 2021].…”

“…These karyotypic characteristics raised interest in the study of the chromosomal evolution process for the family Cervidae, given its importance for their conservation and taxonomy resolution. Intraspecific chromosomal differences can generate an efficient postzygotic reproductive barrier due to their influence on gamete production [Galindo et al, 2021]. Depending on the numerical or structural variation between the chromosomes of 2 individuals, their offspring may be infertile, given that the karyotypic variation may lead to several alterations during meiosis, such as incorrect pairing of parental chromosomes, errors in chromosome segregation and during crossing-over [Cursino et al, 2014;Salviano et al, 2017;Galindo et al, 2021].…”

“…Intraspecific chromosomal differences can generate an efficient postzygotic reproductive barrier due to their influence on gamete production [Galindo et al, 2021]. Depending on the numerical or structural variation between the chromosomes of 2 individuals, their offspring may be infertile, given that the karyotypic variation may lead to several alterations during meiosis, such as incorrect pairing of parental chromosomes, errors in chromosome segregation and during crossing-over [Cursino et al, 2014;Salviano et al, 2017;Galindo et al, 2021]. This high karyotypic variety, commonly observed in deer species as previously stated, is related to events of chromosomal rearrangements [Neitzel, 1987;Fontana and Rubini, 1990;Abril et al, 2010].…”

“…On the other hand, the mechanisms of karyotypic evolution that establish the remarkable chromosomal polymorphisms presented by other groups, such as Neotropical deer, are unexplored and still mostly studied only by classical cytogenetic methods [Duarte and Jorge, 2003;Abril and Duarte, 2008;Abril et al, 2010;Fiorillo et al, 2013;Cifuentes-Rincón et al, 2020]. In this group, the rapid chromosomal reorganization and the observation of intraspecific chromosome polymorphisms evidence a possible ongoing speciation process [Abril et al, 2010;Valeri et al, 2018;Galindo et al, 2021].…”

High richness of non-volant mammals in a seasonal forest fragment in southeastern Brazil

“…(Silva et al, 2019). We consider the red brocket in the area to be Mazama rufa instead of M. americana, following Peres et al (2021).…”