Mating system multiple paternity and effective po

Authors: Kathrin Theissinger N N FitzSimmons C J Limpus C J Parmenter A D Phillott

Publish Date: 2008/04/13

Volume: 10, Issue: 2, Pages: 329-346

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Abstract

In recent years genetic studies have been used to investigate mating systems of marine turtles but to date no such research has been conducted on the flatback turtle Natator depressus This study investigates paternity of flatback turtle clutches at two rookeries in Queensland Australia Peak Island Keppel Bay and Mon Repos Bundaberg In the 2004–2005 nesting season tissue samples were taken from either single or multiple clutches n = 16 of nesting females n = 8 representing a sampling effort ranging from 25 to 50 offspring per nest Determination of the extent of multiple paternity was done using a comparative approach that included initial inferences based on observed alleles Chisquare tests for deviations from Mendelian expectations and three software programs PARENTAGE10 GERUD20 and MER30 Results varied depending on the approach but by calculating a consensus value of the output from these different methods the null hypothesis of single paternity could be rejected in at least 11 of the 16 clutches 69 Multiple paternity was thus observed in the clutches of six of nine females 67 with two or three fathers being the most likely outcome Analyses of successive clutches illustrated that paternal contribution to clutch fertilization can vary through time as observed for two females This first evidence regarding the mating system of flatback turtles indicates that multiple paternity is common in this species and that the observed frequency of multiple paternity is among the higher values reported in marine turtle species Application of these results to estimates of effective population size N e suggests that population size may have been relatively stable over long periods Continued monitoring of population dynamics is recommended to ensure that future changes in the east coast can be detectedField volunteers Jennifer Spilsbury Rick Davis and Matt Münchow helped to sample females monitor nests and collect hatchlings regardless of heat or cyclones Duncan Limpus and Linda Reinhold provided substantial input at Mon Repos Leigh Slater provided samples from nesting females at Curtis Island Niccy Aitken and Alex Quinn helped problem solve various laboratory analyses Prof Dr Alfred Seitz and Dr Habil Jes Johannesen from the Institute of Molecular Ecology Johannes Gutenberg University Mainz Germany provided financial support and comments on the manuscript Special thanks to all of these people for their important contributions All sampling procedures complied with the relevant Australian laws

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