Isolation and characterisation of twelve polymorphic microsatellite markers for Xestospongia spp. and their use for confirming species identity

Barrel sponges are one of the largest and most conspicuous members of the coral reef fauna across the Indo-Pacific that are under threat from habitat degradation. Twelve novel microsatellite markers were developed for Xestospongia testudinaria from 454 sequence data and scored across 47 individual barrel sponges collected from the Sampela reef in the Wakatobi Marine National Park, Indonesia. All loci except one was polymorphic with the number of alleles per locus ranging from 5 to 24. Observed heterozygosity ranged from 0.08 to 0.77 and FIS values ranged from −1.61 to 0.77, with the majority of loci being in Hardy–Weinberg equilibrium (HWE). We then tested our markers on 28 likely Xestospongia bergquistia specimens from the same reef. Observed heterozygosity ranged from 0.23 to 0.593 and FIS values ranged from −0.078 to 0.373; all but two loci were in HWE. Furthermore, we confirmed the differentiation of these two species by Principle Coordinate Analysis and Analysis of Molecular Variance. These markers will be useful for a range of future fine-scale population genetics studies for these two important reef species.