Population Genetics of New Zealand Pagrus auratus and Genetic Variation of an Aquaculture Broodstock
Fisheries and aquaculture are major contributors of nutrition and animal protein worldwide. Understanding the genetic variation and differentiation within and between wild populations is important for both sustainable fisheries management and selection of aquaculture broodstock. This study determined the genetic variation and differentiation of New Zealand Pagrus auratus based on mitochondrial DNA control region sequencing and microsatellite DNA genotyping. Low but significant differentiation was measured between several sample sites, but otherwise the population was genetically panmictic. The M-ratio test and Fu’s Fs statistics indicate that there may have been historical bottlenecks at all sample sites and a more recent bottleneck in the Tasman Bay. Two South Island sites were identified that had not been through recent bottlenecks and were not significantly differentiated from the Tasman Bay, which may provide a source of gene flow to aid its genetic recovery. Comparison of the broodstock and wild genetic variation indicate that the broodstock represented most of the genetic variation found in high frequency in wild populations, but further wild-caught individuals may be needed, based on the criteria used in several previous studies. Simulations indicate that adding approximately 20 and 48 wild-caught individuals from multiple populations to the current broodstock was needed to represent all genetic variation above a target frequency of 0.05 in the Tasman Bay and all sample sites, respectively.