ABSTRACT Two species of Callithrix, C. jacchus (Linnaeus, 1758) and C. penicillata (É. Geoffroy, 1812), are considered invasive in Rio de Janeiro. This study determined the genetic and morphological diversity and verified the species involved in the hybridization of 10 individuals from the municipalities of Silva Jardim (N = 9) and Rio das Ostras (N = 1). We compared the external morphology and skull of C. jacchus (N = 15) and C. penicillata (N = 14) specimens deposited in the collection of the National Museum of Rio de Janeiro (MN- UFRJ). Phylogenetic (maximum likelihood and Bayesian inference) and phylogeographical analyses (network analysis) were performed based on cytochrome b sequences. These analyses included hybrids from the metropolitan region of Rio de Janeiro (N = 3), C. penicillata (N = 2), C. jacchus (N = 2), C. geoffroyi (N = 2), C. kuhlii (N = 2), C. aurita (N = 1), and as outgroups, Mico emiliae (N = 1) and Saguinus mystax (N = 1). The pelage and skull characters of most hybrids were more closely related to C. jacchus. Skull morphometric analysis revealed an intermediate state for the hybrids. Phylogenetic analyses revealed a high similarity between the hybrids and C. penicillata. Six haplotypes of hybrids were identified. Network analysis including them and C. penicillata recovered the topology generated by phylogenetic analysis. The results corroborate that C. jacchus and C. penicillata participate in the hybridization process. There was no geographic structure between hybrids from the coastal lowlands and from the metropolitan region of Rio de Janeiro.

Kerodon rupestris (Wied, 1820) é a espécie mais especialista entre os roedores caviídeos endêmica dos afloramentos rochosos da região semiárida do Brasil, a Caatinga. No presente trabalho foram descritos diferentes cariótipos para K. rupestris, baseado em amostras coletadas em Itapajé, Ceará (CE), Iraquara na Bahia (BA) e Botumirim em Minas Gerais (MG). As amostras incluem populações do norte, centro e sul da distribuição da espécie. Os resultados foram comparados com um cariótipo de Pernambuco, previamente descrito para a espécie. O número diploide (2n = 52) foi constante para as populações analisadas, mas o número fundamental (FN) variou de 92 em Itapajé (CE) e Iraquara (BA), para 94 em Botumirim (MG). Inversões pericêntricas afetando um pequeno par de cromossomos acrocêntricos podem explicar essa variação. Bandas C mostraram que a heterocromatina constitutiva estava distribuída na região pericentromérica de todos os cromossomos, constante para todas as amostras estudadas. Sítios de NOR foram encontrados nos pares de cromossomos 10 e 11, também constantes para todas as populações. O cromossomo X é inteiramente heterocromático, com grande concentração de heterocromatina nas porções intersticial e distal dos braços. Diferenças na composição cromossômica nas amostras de Botumirim são congruentes com os resultados prévios sobre a variabilidade cranial: os indivíduos de Botumirim apresentaram tamanho cranial maior do que os de outras populações no espaço de caractereres multivariados. Uma vez que Botumirim está a apenas 100 Km de distância da localidade-tipo, propõe-se -de acordo com os resultados publicados previamente- que o FN para a espécie seja classificado como politípico (94/92).

Kerodon rupestris (Wied, 1820) is the most specialized species among caviid rodents and is endemic to the extensive rocky outcrops in the semi-arid region in Brazil. Herein we describe different karyotypes for K. rupestris, based on samples collected in Itapajé, Ceará (CE), Iraquara in Bahia (BA), and Botumirim in Minas Gerais (MG). Our samples included northern, center and southern populations in the range of the species distribution. The results were compared with a karyotype from Pernambuco previously described for the species. The diploid number (2n = 52) was constant among the analyzed population samples, but the fundamental number (FN) varied from 92 in Itapajé (CE) and Iraquara (BA), to 94 in Botumirim (MG). Pericentric inversions affecting one small pair of acrocentric chromosomes may explain this variation. C-Bands showed that constitutive heterochromatin was distributed in the pericentromeric region of all chromosomes, constant for all examined populations. NOR sites were found in chromosomes pairs 10 and 11, constant for all populations. X chromosome was entirely heterochromatic, with greater heterochromatin concentration in interstitial and distal parts of the arms. Y chromosome was completely heterochromatic. Differences in chromosomal composition in Botumirim sample are congruent with the results of previous studies about cranial variability: Botumirim had the largest cranial size and was discriminated from other population samples in the multivariate character space. Since Botumirim is only 100 Km away from the type locality, it is proposed-in congruence with previously published results-that the FN for the species is polytypic (94/92).

Glossophaga soricina soricina (Pallas, 1766) plays an important role in the ecosystems where it is found, taking part in the pollination of hundreds of plant species. Here, we statistically compared 12 external characters of 169 specimens collected in three Brazilian biomes: 82 in the Pantanal (Mato Grosso), 45 in the Atlantic Forest (Ilhéus, Bahia) and 42 in the Caatinga (Chapada Diamantina, Bahia). Each character was analyzed by descriptive and inferential statistics. The t-test didn't detect any differences between males and females of each population. The ANOVA with a posteriori Tukey test showed significant results for all traits (Forearm length, Calcar length, Body length, Tail length, Hindfoot length, Ear length, Tragus length, Thumb length, Noseleaf length, Noseleaf width and Horseshoe width) except for Tibia length. The discriminant analysis showed distinct clusters representing the populations of each biome. The tests demonstrated that the three populations are significantly different from one another and that the specimens of the population from the Caatinga, on average, are larger than those from the Pantanal, which are larger than those from the Atlantic Forest, confirming the possible existence of intra-specific geographic variation.

A new karyotype of Wiedomys pyrrhorhinus (Wied, 1821) is described, including G- and C-banding and Ag-NOR sites from specimens collected in the municipality of Morro do Chapéu, situated in the northern region of the Chapada Diamantina, state of Bahia. Karyological studies of W. pyrrhorhinus have shown a constant diploid number (2n) of 62 with two different numbers of autosomal arms (FNa): 86 and 90, respectively. The new karyotype revealed 2n = 62 and FNa = 104, being the higher autosomal number found so far for this genus. The X chromosome is a large acrocentric and the Y chromosome is a small acrocentric. The analysis of the karyotype morphology suggests that this new karyotype is more closely related to the previous karyotype with 2n = 62 and FNa = 90, described from Caetité, Bahia State. Further studies, comparing different populations of W. pyrrhorhinus, including molecular approaches, may help to better understand the geographical limits of each population and their phylogenetic relationships in the Caatinga biome

Species of the didelphid genera Gracilinanus and Cryptonanus are morphologically and cytogenetically very similar. Several qualitative characters, some of which exhibit intraspecific polymorphisms, have been used to distinguish these genera, but more data are needed to characterize them better. Samples of G. agilis and Cryptonanus spp. from nine localities in central and northeastern Brazil were analyzed. Multivariate analyses of craniodental measurements and descriptive statistics of external body measurements indicate that G. agilis is conspicuously larger than Cryptonanus spp., and that general size is the main factor distinguishing these forms. Size differences can be combined with qualitative characters making the differentiation between G. agilis and Cryptonanus spp. easier. Cytogenetic analyses, including the first description of C-bands and Ag-NORs of G. agilis, revealed that the karyotypes of G. agilis and Cryptonanus sp. from Barão de Melgaço, Mato Grosso, are very similar, except for the fourth autosomal pair and the X chromosome.

Los didélfidos Gracilinanus y Cryptonanus poseen una morfología y citogenética muy semejantes. Estos géneros han sido diferenciados por caracteres polimórficos cualitativos, pero más datos son necesarios para caracterizarlos mejor. Fueron analizadas muestras de G. agilis y Cryptonanus spp. de nueve localidades de centro y nordeste de Brasil. Los análisis multivariados de las medidas craneodentarias y las estadísticas descriptivas de las medidas corporales externas indican que G. agilis es claramente mayor que Cryptonanus spp. y que el tamaño general es el principal factor para distinguir esas formas. La variación en tamaño puede ser asociada a los caracteres cualitativos para facilitar la diferenciación entre G. agilis y Cryptonanus spp. Los análisis citogenéticos, incluyendo la primera descripción del bandeo C y las Ag-NORs de G. agilis, revelaron que los cariotipos de G. agilis y Cryptonanus sp. de Barão de Melgaço, Mato Grosso, son muy semejantes, excepto por el cuarto par de autosomas y el cromosoma X.

The karyotype of Dasyprocta azarae has not been described previously. In this article we describe the karyotype of D. azarae from Northern Pantanal, Mato Grosso, Central Brazil. D. azarae has a diploid number 2n=64 and a number of autosomal arms NA=122. The 2n and NA are the same as those reported for other Brazilian species of Dasyprocta, but differ in chromosome morphology. Differences in the sex chromosomes were also found. The Y chromosome is acrocentric whereas in other Dasyprocta species is metacentric or submetacentric. The C-banding pattern coincides with that described for other species, except for pair six, having two bands of heterochromatin. The NOR patterns revealed intraindividual variation, with 1 to 6 NOR chromosomes. In the other species of Dasyprocta the NOR is present in only 1 pair. Although few data about morphological variation is available and restricted to color pattern, the small chromosomal differences observed among species of Dasyprocta are however, capable to differentiate taxa of the genus.

En este artículo se describe por primera vez el cariotipo de D. azarae procedente del norte del Pantanal, Mato Grosso, Brasil. La especie posee un número diploide 2n=64 y un número de brazos autosómicos NA=122. Los resultados para 2n y NA son los mismos que los encontrados para otras especies brasileñas de Dasyprocta, pero difieren en la morfología cromosómica. También fueron identificadas diferencias en los cromosomas sexuales. El cromosoma Y es acrocéntrico en ésta, mientras que en otras especies del género es metacéntrico o submetacéntrico. El patrón de bandas C es igual al descrito para otras especies, con la excepción del par seis, que presenta dos bandas de heterocromatina. Los patrones NOR demuestran variación interespecífica, con uno a seis cromosomas marcados con NORs. En otras especies de Dasyprocta el NOR está presente en apenas un par. Aunque hay poca información disponible sobre variación morfológica, restringida al patrón de color, las pequeñas diferencias cromosómicas entre especies de Dasyprocta son, sin embargo, capaces de diferenciar taxas del género.