Multiple paternity in side-neck turtles Podocnemis expansa: evidence from microsatellite DNA data

Multiple paternity was found in two clutches of Podocnemis expansa using eight microsatellite loci. When loci were analysed separately a minimum of two males was estimated for nest N23, and three for nest C17. When all loci were combined, three patrilines were detected in N23, and six in C17. The distribution of full-sib cluster sizes indicated a disproportionate contribution of one male to clutch C17, consistent with possible sperm competition, or the mixing of leftover and newly acquired sperm. High mutation rates were detected at several loci. Multiple paternity has positive implications for this endangered species as it may slow the loss of genetic variability caused by drift. This is the first report of multiple paternity in the suborder Pleurodira.