Background: The protozoan Trypanosoma cruzi circulates in semiarid areas of northeastern Brazil in distinct ecotopes (sylvatic, peridomestic and domestic) where Triatoma brasiliensis Neiva, 1911 is the most important Chagas disease vector. In this study, we analyzed microevolutionary and demographic aspects of T. brasiliensis populations at the ecotypic, micro and macro-geographic scales by combining morphometrics and molecular results. Additionally, we aimed to address the resolution of both markers for delimiting populations in distinct scales. Methods: We sampled populations of T. brasiliensis from distinct ecotypic and geographic sites in the states Rio Grande do Norte (RN) and Paraíba (PB). The geometric morphometry was carried out with 13 landmarks on the right wings (n = 698) and the genetic structure was assessed by sequencing a region of cytochrome b mitochondrial gene (n = 221). Mahalanobis distance (MD) and coefficient of molecular differentiation (Φ_ST) were calculated among all pairs of populations. The results of comparisons generated MD and Φ_ST dendrograms, and graphics of canonical variate analysis (CVA). Results: Little structure was observed for both markers for macro-geographic scales. Mantel tests comparing geographic, morphometric and genetic matrices showed low correlation (all R² < 0.35). The factorial graphics built with the CVA evidenced population delimitation for the morphometric data at micro-geographic scales. Conclusions: We believe that T. brasiliensis carries in its genotype a source of information to allow the phenotypical plasticity across its whole distribution for shaping populations, which may have caused a lack of population delimitation for CVAs in morphometric analysis for macro-geographic scale analysis. On the other hand, the pattern of morphometric results in micro-geographic scales showed well-defined groups, highlighting the potential of this tool to inferences on the source for infestation.

Two species of manatees are found in Northern Brazil—the Antillean manatee (Trichechus manatus), which is found along the coast from Florida to Northeastern Brazil, and the Amazonian manatee (Trichechus inunguis), endemic to the Amazon drainage basin. These species show a sympatric distribution in the region of the Marajó Archipelago, an estuarine area surrounding the Amazon River mouth. There is evidence of the occurrence of interspecific hybrids in this area, based on mitochondrial DNA analyses, although the use of nuclear markers has not corroborated this proposal. Considering that these species show very distinct karyotypes, despite being closely related (2n = 48 in T. manatus and 2n = 56 in T. inunguis), hybrids would present distinct chromosome numbers. Based on this, we conducted cytogenetic analyses using classic and molecular techniques in three calves found stranded in the Marajó Island and Amapá coast. The results showed that one of them, morphologically classified as T. inunguis, presented the correspondent karyotype, with 2n = 56. However, the other two, which were phenotypically similar to T. manatus, showed 2n = 49. Despite the same diploid number, their G-banding patterns revealed some differences. The results of the distribution of some microsatellite sequences have also confirmed the heterozygosity of some chromosomal pairs in these two individuals. These results are the first indubitable confirmation of the occurrence of natural hybrids between T. manatus and T. inunguis, and also brings about some issues concerning the viability of hybrids, considering that these two individuals do not correspond to an F1 hybrid, but instead, both presented a possible F2 karyotype.

The human population of the Brazilian Amazon possesses a rich body of beliefs and practices that relate to river dolphins, which are also known as botos (Inia and Sotalia species). There is a widespread belief in their magical powers in relation to love enchantments. One form that this takes is ‘dolphin love charms’ and these are widely in use in northern Brazil, and also in the largest southern cities. This paper considers the trade of cetacean products in the form of love charms in Brazil. Samples were obtained in the north (n=70), northeast (n=3) and southeast (n=59) regions from 34 shops or municipal markets. A total of 38 of the 131 collected samples were evaluated by complete cytochrome b sequencing, revealing the use of two species: the Guiana dolphin (Sotalia guianensis) (n=3) and the domestic pig (Sus scrofa) (n=10) and samples containing no animal material (n=10) were also detected. Pigs are used to fake love charm products in Rio de Janeiro. However, whereas in the southeast there is no actual use of dolphin tissues in love charms, there is a widespread use of dolphin tissue in northern Brazil, including, muscle, eyes, penis and vagina. The data confirm a regular trade of dolphin products in large cities in the north and northeast of Brazil and the need for more intense actions from governmental agencies in order to curb this illegal trade.

A large geographic differentiation has been reported in Sylvilagus brasiliensis based on external characters and a small number of samples. Karyologic and molecular studies as well as new sampling efforts are need to a better understanding of the S. brasiliensis complex diversity. A new karyotype with 2n=40 and FNa=74 from Rio de Janeiro is here reported. Phylogenetic analyses based on cytochrome b DNA sequence of eight samples from the states of Paraíba, Tocantins, Goiás, Minas Gerais and Rio de Janeiro suggested a strong structured population. Both, molecular and karyotypic data suggest that the diversity in the study area may be larger than that reported in the literature on the basis of external characters.