Short Communication Polyandry in the red-headed river turtle Podocnemis erythrocephala (Testudines, Podocnemididae) in the Brazilian Amazon (original) (raw)
Related papers
Genetics and Molecular Research, 2017
The aim of the present study was to investigate the reproductive behavior of the giant Amazon River turtle (Podocnemis expansa) in the Amazon. This was carried out by estimating the degree of polymorphism in five DNA microsatellites in a sample of 359 hatchlings from 12 nests in the Mamirauá Sustainable Development Reserve in the municipality of Tefé, state of Amazonas, Brazil. An analysis of allele frequency and variation in the five microsatellite loci allowed for determination of multiple paternity in all nests sampled. Contributions of at least four male turtles to one nest, three male turtles to six nests, and two male turtles to five nests were identified. Knowledge on the reproductive behavior of P. expansa can assist in the establishment of management and conservation strategies for the population in the Mamirauá Reserve.
Amphibia-reptilia, 2008
We used eight microsatellite loci to investigate the mating system in P. unifilis. DNA samples were collected from 66 hatchlings sampled from six nests on a central Amazon River beach near Barreirinha, Amazonas, Brazil. We found that P. unifilis females exhibited a promiscuous mating system (polyandry) with all nests being fathered by at least two males. The presence of multiple males contributing to each clutch was ascertained by the presence of at least two extra alleles in multilocus genotypes in each nest. Our data demonstrate that polyandry seems to be the prevalent system of mating in this endangered species.
Podocnemis sextuberculata (Pleurodira: Podocnemididae) is widely distributed throughout the Amazon drainage basin in Brazil, Colombia, and Peru. Telemetry and previous molecular data suggest that P. sextuberculata lacks population structure in the central Amazon basin of Brazil. Generalization of these results, however, requires much-broader sampling across a range of habitats of this broadly distributed species. For this reason, we tested the hypothesis of panmixia in P. sextuberculata, analyzing a total of 319 specimens sequenced for the mitochondrial control region. Our sampling included localities from 16 areas in the Amazon basin from rivers characteristic of the Amazon basin (whitewater), clearwater rivers of the Guiana shield (Branco, Trombetas, and Nhamund´a rivers), and the Brazilian shield (Xingu River). The hypothesis of panmixia was rejected because the results of analysis of molecular variance, pairwise VST, and Bayesian analysis of population structure indicated population structure in the group of individuals from the locality of Xingu which was not correlated to a pattern of isolation by distance. We suggest that the populations of P. sextuberculata of the Brazilian Amazon basin are composed of 2 management units, one represented by populations restricted to the Xingu River and the other represented by all other populations. The population of the Xingu should be viewed with attention and concern, especially considering the direct and indirect impacts of damming the Xingu River.
2006
We used genetic data from 7 microsatellite loci to determine the frequency of multiple paternity in clutches of giant Amazon river turtles, Podocnemis expansa, from the Orinoco River in Venezuela. Among hatchlings sampled from 32 clutches, paternity analysis found that a minimum of 10.3% could conclusively be shown to have been sired by more than one male. We contrast this result with those from another population of this species, as well as other species of turtles, and discuss the importance of documenting patterns of paternity in different populations of a given species and considering the effects of ecological differences among populations on female mating behavior.
Latino American Journal Aquatic Reserach, 2018
The incidence of multiple paternities in two populations of Podocnemis expansa of Brazilian Amazon both rose in captivity and in natural habitat, was verified by using five microsatellite loci. Three hundred twenty-seven offspring from two different sampling sites were genotyped. The analysis revealed a 100% rate of multiple paternities in both populations. The Mendelian distribution of the alleles found in each nest was used to determine the number of contributing males. It was estimated that at least ten males contributed to each brood in captivity and nine contributed to each brood in the wild. These values are the highest ever recorded for the number of contributing P. expansa males. The findings have considerable implications regarding the conservation of this species, given that multiple paternities is important to the maintenance of genetic variability and has important consequences in increasing the effective size of a population in comparison to single paternities.
Molecular Ecology Notes, 2007
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 .
ContextWaterfalls and rapids of Amazon basin have been suggested as causing the speciation and genetic structure of many freshwater species, including turtles. The species behavior affects the way waterfalls and rapids limit gene flow. The Yellow-spotted River Turtle (Podocnemis unifilis), a widely distributed and endangered Amazonian turtle, does not show the habit to migrate long distances for breeding or eating, but has a complex geographic pattern of genetic variation.ObjectivesHere, we investigate isolation by distance and by resistance of P. unifilis. We analyzed if the species ecological niche and waterfalls explain the genetic distance in Brazilian Amazonia.MethodsWe evaluated the P. unifilis spatial distribution of genetic variability and diversity using the control region of mitochondrial DNA. We tested the hypotheses of isolation either by distance and resistance through an integrative approach using genetic, geographic, and ecological data. We created a resistance matrix...
2008
We studied the population genetics of Podocnemis unifilis turtles within and among basins in the Orinoco and Amazon drainages using microsatellites. We detected high levels of genetic diversity in all sampled localities. However, 'M-ratio' tests revealed a substantial recent population decline in ten localities, in accord with current widespread exploitation. Our results reveal a consistent pattern across multiple analyses, showing a clear subdivision between the populations inhabiting the Amazon and Orinoco drainages despite a direct connection via the Casiquiare corridor, and suggesting the existence of two biogeographically independent and widely divergent lineages. Genetic differentiation followed an isolationby-distance model concordant with hypotheses about migration. It appears that migration occurs via the flooded forest in some drainages, and via river channels in those where geographic barriers preclude dispersal between basins or even among nearby tributaries of the same basin. These observations caution against making generalizations based on geographically restricted data, and indicate that geographically proximate populations may be demographically separate units requiring independent management.
Contributions to …, 2007
The Magdalena River Turtle (Podocnemis lewyana) is a Colombian endemic species, endangered due to human exploitation and habitat destruction. To date, this species is poorly known ecologically and data on its genetic diversity are lacking. Here we report on the fi rst genetic survey of the species across its distribution range. We obtained mitochondrial DNA sequences (488 bp) of the cytochrome b gene from 109 individuals. Samples belong to populations located at several different localities, grouped in fi ve regions, along the four main river basins: Magdalena, Cauca, San Jorge, and Sinú drainages. We found two haplotypes, which differ in only one nucleotide substitution and which are represented with different frequencies in the fi ve geographic regions. These results suggest that P. lewyana harbors little genetic variation and is a genetically uniform species, but more variable markers (i.e., microsatellites) should be used to unravel fi ne-scale phylogeographic structures in this species.
Genetics and Molecular Research, 2016
Genetic studies of multiple paternity are a valuable tool to gain information on the reproductive biology of turtles. We analyzed paternity type in Podocnemis sextuberculata and related number of fathers per nest to nesting period (beginning, middle, or end of nesting season); clutch size (number of eggs); female size; and hatchling success. Females were captured and maximum linear carapace lengths measured during the 60 days that encompass the nesting season at Rio Trombetas Biological Reserve (Pará, Brazil). Nests were marked and blood samples collected from hatchlings. Six heterologous loci were used: five from Podocnemis unifilis and one from Podocnemis expansa. Hatchlings were analyzed from 23 nests, and the rate of multiple paternity was 100%. The mean number of fathers per nest was six (± 0.9), and no significant difference between number of fathers in a nest and nesting period. Similarly there was no significant relationship between number of fathers in a nest and female F.P. Freda et al. ©FUNPEC-RP www.funpecrp.com.br Genetics and Molecular Research 15 (1): gmr.15017335 size or hatchling success rate. Number of fathers was, however, positively correlated with clutch size (Spearman correlation rho = 0.47; P > 0.05). To our knowledge, this is the first study to test the relationship between multiple paternity and ecological aspects of the reproductive ecology of turtles in the genus Podocnemis.