Múltipla paternidade e razão sexual da população reprodutiva de dermochelys coriacea (Vandeli, 1761) do Espírito Santo

Abstract

Accessing sea turtles' mating patterns and behavior is challenging, as they are difficult to observe due to their coastal and oceanic habitats. Molecular biology techniques, such as microsatellite marker genotyping, have been useful in filling some of these observational gaps. Microsatellite markers have been used in population genetics studies due to their high variability and high mutation rate. Because of this characteristic, these markers are applicable in paternity studies as there is a low probability that individuals share the same alleles at different loci. This methodology has been widely explored to investigate multiple paternity in sea turtles, analyzing the possibility of more than one male contributing to each clutch. The present study investigated the level of multiple paternity and the sex ratio of the reproductive population of the leatherback turtle Dermochelys coriacea, a “critically endangered” species, at beaches close to the river Doce mouth, in Linhares, Espírito Santo State, Brazil. This was the first study of multiple paternity in a Brazilian leatherback turtle population. Fifteen clutches from two consecutive seasons (2019/20 and 2020/21) were examined using six microsatellite markers. The results revealed multiple paternity in 60% of the clutches, and 41% of polygyny, with 1 to 6 males per clutch, and a sex ratio of 1.42 males for each female. This study provides a basis for future comparisons with other populations in Brazil to estimate the reproductive sex ratio of the species on the Brazilian coast, providing scientific support to understand male gene flow better and to prioritize conservation measures for leatherback sea turtles.