We developed specific primers for microsatellite DNA regions of Podocnemis unifilis and tested their utility in population genetic and paternity studies on the species and other closely related Amazonian chelonians. Seventeen microsatellite loci were polymorphic in P. unifilis and all, plus two monomorphic microsatellites in P. unifilis, were polymorphic in at least one additional chelonian species, including Peltocephalus dumeriliana .

ABSTRACT. The genus Podocnemis comprises six living species, including P. erythrocephala (irapuca -red-headed river turtle). Data are available concerning the reproductive biology of the species of the genus Podocnemis, but little is known about their reproductive strategies. Considering the total lack of such data for P. erythrocephala, and with the goal of contributing information on their mode of reproduction, we examined the relationships among individuals of nests of this turtle, using microsatellite markers. Using four microsatellite loci, we analyzed the progeny in six nests from two localities in the Brazilian Amazon (Santa Isabel do rio Negro and Parintins). All juveniles from each nest were analyzed. The genotypes of each juvenile from each nest were identified, and because a sample of female DNA was not available, the maternal genotype was inferred from homozygous individuals in each nest. We found that this species is promiscuous; there was multiple paternity in five of the six nests analyzed. In addition to being important for the understanding of evolutionary and genetic processes, this type of information will be useful for chelonian management projects. Our data suggest one possible difference between reproductive patterns of the different populations. This multi-paternal condition may be a natural reproductive strategy for the preservation of the genetic diversity of this species.

ABSTRACT. The chelonians are, in general, important for the economy of the traditional populations of the Amazon region, especially as a source of animal protein. Furthermore, sub-products, such as eggs and fat, are utilized in the manufacture of cosmetics, and the plastron and carapace are used in the manufacture of adornments. The freshwater turtle species Podocnemis sextuberculata, locally known as "iaçá" or "pitiú", is widely distributed in the Amazon Basin in Brazil and also in Colombia and Peru. This species is on the International Union for Conservation of Nature Red List in the category of vulnerable species. We examined the genetic variability and population structure of three populations represented by 64 individuals sampled from Reserva Federal de Abufari, Tapauá, Amazonas State; Reserva de Desenvolvimento Sustentável Mamirauá, Tefé, Amazonas State, and Terra Santa, Pará State. All of these are over 1000 km from each other. A partial 415-bp sequence of the mitochondrial gene ND1 was utilized as a molecular marker. Seven haplotypes were observed; the most common haplotype was shared by all the areas sampled, while the rarest haplotypes were represented by a single individual and were thus restricted to a single locality. The sharing of the most common haplotype, the high number of migrants (Nm) and the AMOVA results indicate a lack of genetic structure among the sampling localities. The levels of genetic variability observed were homogeneous among the sampling localities. These results (Ө ST and Nm) are compatible with what is known about the ecology of this species, which has a great migratory capacity.

Evidence of multiple paternity in Podocnemis sextuberculata (Testudines: Podocnemididae) detected by microsatellite markers. We found evidence of multiple paternity in a sample of 12 Podocnemis sextuberculata nests including seven nests (80 hatchlings) collected along the Amazonas River, in the municipality of Barreirinha, AM, As observed in other species of the genus, P. sextuberculata also presented polyandric behavior. By means of allelic frequency and variation in six microsatellite loci for each location, the occurrence of multiple paternity in sampled nests of this species was inferred, even though the maternal genotype was unknown. For one of the nests, a minimum of four males contributed to the clutch, whereas for nearly all remaining nests at least two males contributed. Only one of the twelve nests did not show clear evidence for contributions from more than one male P. sextuberculata.Keywords: mating system, paternity, Podocnemis, reproduction, turtles.Resumo Evidência de contribuição paterna múltipla em Podocnemis sextuberculata (Chelonia: Podocnemididae) por meio de marcadores microssatélites. Encontramos evidências de paternidade múltipla em uma amostra de 80 recém-eclodidos de sete ninhos de Podocnemis sextuberculata situados ao longo do rio Amazonas, no município de Barreirinha, AM, Brasil, e 54 indivíduos recém-eclodidos de cinco ninhos na Reserva Biológica Abufari, Tapauá, AM, Brasil. Como observado em outras espécies do gênero, P. sextuberculata apresentou comportamento poliândrico. Por meio da frequência alélica e variação em seis locos microssatélite para cada localidade, a ocorrência de 90Phyllomedusa -14(2), December 2015 paternidade múltipla em ninhos amostrados dessa espécie foi inferida, mesmo o genótipo da mãe sendo desconhecido. Para um dos ninhos, um mínimo de quatro machos contribuíram para a prole, enquanto que para quase todos os outros ninhos, pelo menos dois machos contribuíram. Apenas um dos 12 ninhos não mostrou evidência clara de contribuição de mais de um macho. Esta é a primeira evidência genética de paternidade múltipla em P. sextuberculata.