The diversity of cichlid fish in Lake Victoria has rapidly declined in recent years in due in great part to the introduction of exotic species. The Lake Victoria Cichlid Species Survival Plan is a captive breeding program whose goal is to preserve and possibly reintroduce many of these dwindling species. Successful breeding protocols for these cichlids would conserve genetic diversity, but few studies have actually measured genetic diversity of captive populations. In the current study we use data from twelve microsatellite DNA markers to investigate the maintenance of genetic diversity of the Lake Victoria cichlid Haplochromis piceatus in five zoo populations, including offspring from the original captive population at Leiden University. In addition, changes allele frequencies across three generations of the largest US population (Toledo, OH) were used to estimate the effective population size by the temporal method.
Results/Conclusions
Preliminary results from five loci among three zoo populations show an average heterozygosity ranging from 0.47 (San Antonio and Moody Gardens) to 0.62 (Toledo). An average of 6 alleles per locus were found in Toledo, as compared to less than 3 in the other populations, and roughly half of all alleles observed were private alleles found only in the Toledo population. An analysis of molecular variance showed 6% of the total genetic diversity is maintained between zoo populations from different institutions, though pairwise FSTs reveal no population structure between San Antonio and Moody Gardens. Twelve microsatellite loci amplified from three generations of Toledo H. piceatus (20/generation) were used to estimate Ne, which was found to be 10 individuals, more than an order of magnitude smaller than the actual census (between 180-450 animals). The Toledo breeding program appears to be more effective at maintaining or at least slowing the loss of genetic diversity from this captive species, with little additional diversity being found in at least two of the remaining four zoo populations.
