Investigating the reproductive behaviour of the green sea turtle
(Chelonia mydas) using parentage analysis
- Violaine Dolfo,
- Cécile Gaspar,
- Miri Tatarata,
- Emilie Boissin,
- Serge Planes
Miri Tatarata
Direction de l'Environnement de la Polynésie Française
Author ProfileAbstract
The reproductive systems of natural populations can greatly impact their
genetic diversity by preventing or encouraging inbreeding. It is
therefore crucial to have a comprehensive understanding of the mating
system to evaluate a population's ability to maintain genetic diversity
over time. In this study, we examine the mating system of an endangered
population of green sea turtles in Tetiaroa, French Polynesia. We
determine if different mating behaviours serve as strategies to avoid
inbreeding. We genotyped 107 nesting females and 1483 hatchlings from
549 nests and used 23 microsatellite markers to reconstruct the
genotypes of the fathers. We assessed the level of inbreeding and
relatedness of the parent pairs and explored the correlation between
relatedness and fitness parameters in the offspring. We determined the
mating behaviours of both males and females and investigated if specific
behaviours were linked to different levels of relatedness. Our results
showed that 27 fathers and 31 mothers were responsible for the genotypes
of 445 hatchlings from 105 nests. Global Fis was significant, and levels
of relatedness were higher than expected through random mating,
indicating inbreeding and non-random partner selection. However, we did
not find any mating behaviours that were associated with lower
relatedness levels than the general population, suggesting that they are
not part of an inbreeding avoidance strategy. Ultimately, this study
illuminates the reproductive system of green turtles and shows that this
population is susceptible to inbreeding. Additionally, our research
demonstrates the effectiveness of parentage analysis in understanding
the reproductive behaviour of elusive species.