Molecular analyses
Total genomic DNA was extracted using the QIAamp 96 DNA QIAcube HT Kit and the QIAcube DNA extraction robot (QIAGEN, Hilden, Germany) following the manufacturer’s protocol with modification as described in Dolfo et al. (2023). Samples were genotyped at 23 microsatellite loci using five multiplex reactions as per Dolfo et al. (2023) (GenBank accession number: OQ162049-OQ162073). Allele sizes were visually assessed using GENEMAPPER software v.5 (Applied Biosystems). All ambiguous peak profiles were considered as missing data and only individuals with missing data which occurred at 3 loci or less were kept for the analyses. MICROCHECKER v.2.2.3 (Van Oosterhout et al., 2004) was used to identify null alleles, stuttering errors, and large allele dropout. In total, 1592 hatchling and female genotypes were kept for further analyses.