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.

South America is unique as it is home of two species of manatees: the West Indian manatee, Trichechus manatus, and the Amazonian manatee, T. inunguis. These species are easily identified by the belly skin coloration, the first is entirely gray whereas T. inunguis has a white mark pattern in the belly, and presence of nails in T. manatus, absent in T. inunguis. The morphology and the range of Trichechus species have been clearly established. However, we show that the belly skin coloration and the presence of nails on the pectoral flipper may be polymorphic. These findings prompted us to check all available information about the manatee. In view of lack of accurate data on manatee locations, we produced a gazetteer and a map of Trichechus spp. in South America using records obtained by regular monitoring of aquatic mammal strandings conducted by the Grupo de Estudos de Mamíferos Aquáticos da Amazônia of the Museu Paraense Emílio Goeldi, all available peer-reviewed data, reports, thesis, and newspaper files with photos showing diagnostic characters. These findings showed the need of improving the identification of these species before implementing conservation strategies. Finally, we present a complete report on the extant distribution of these species in South America.

Note on the group size and behavior of Guiana dolphins ( Sotalia guianensis ) (Cetacea: Delphinidae) in Marapanim Bay, Pará, Brazil