The application of microsatellite DNA markers for forensic analysis of koi carp (Cyprinus carpio)

We describe the use of microsatellite DNA markers, previously developed for common carp, to investigate a forensic case involving ornamental koi carp. Two South African breeders offered koi strains for sale, which a third breeder claimed were taken illegally from his ponds. Screening of four microsatellite markers provided polymorphic results for koi, demonstrating their applicability for forensic studies. Amplification product sizes were comparable to those published for common carp at three of the four loci. We observed higher allelic diversity among koi carp than had been reported for a panel of inbred common carp. Coefficients of population differentiation showed no significant differences between the populations involved. Consequently, our analyses could not convincingly prove or disprove foul play. The latter ambiguity was most likely the result of sampling constraints rather than the suitability of the markers. Our results provide a foundation for future application of microsatellite markers for forensic investigation, marker-assisted breeding, and population diversity analysis in koi.