Múltipla paternidade e razão sexual da população reprodutiva de Caretta Caretta
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Data
2019-02-22
Autores
Ferreira, Lais Amorim
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Universidade Federal do Espírito Santo
Resumo
Many aspects of marine turtle biology are very difficult to evaluate because they are highly migratory animals and the lack of information can harm conservation efforts. Characterization of a marine turtle’s mating system is essential for their conservation, since male reproduction patterns and paternal contributions to nests can directly affect the genetic diversity of populations. No paternity tests have been performed for Brazilian marine turtles so far. The aim of this study was to test the hypothesis of multiple paternity for loggerheads turtle’s nests from Povoação beach, near Doce River mouth, Espírito Santo State, in southeastern Brazil. We have analyzed samples from 15 females and 10-20 hatchlings of their nests obtained during one nesting season (2017/2018). We have amplified five polymorphic microsatellites markers for all individuals sampled and, using specific softwares, found that 46 - 86% of clutches sampled had multiple fathers with an average of 1.57 – 2.0 fathers per nest (1-3 fathers found). We also found no evidences of polygyny because no individual fathers contributed for more than one nest in the season analyzed. This is the first study showing polyandry for marine turtles from Brazil and other studies should be done to understand if it is an isolated aspect of loggerheads turtles from Brazil or it is a common pattern. Other studies around the world have shown multiple paternity for loggerheads turtles. The pattern variation found for individual studies could be related to offspring sex ratios produced by sand temperature in distinct nesting places, the phylopatric behavior of male’s individuals and female’s migrations patterns that enable a variety of matings during migration routes. More studies involving other close by loggerheads Brazilian populations and using the same set of molecular markers must be done to understand if individual males can be contributing to different breeding populations and if the amount of multiple paternity will contrast for different locations and distinctive sand temperature. The results of this work are also showing that the genetic diversity of Povoação Beach is being underestimated by using only mitochondrial molecular markers and that multiple males are contributing to increase the levels of genetic diversity for the second largest nesting population of loggerheads turtles from Brazil.
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Poliandria , Tartaruga cabeçuda , Diversidade genética , Tartaruga marinha , Polyandria , Loggerhead turtle , Genetic diversity , Marine turtle