DNA fingerprints of orange roughy,Hoplostethus atlanticus: a population comparison

Genetic variability among Hoplostethus atlanticus collected from two spawning grounds east and west of New Zealand was examined using DNA fingerprints as revealed by hybridization with three clonal probes: 33.15, M13 and 3HVR. The 33.15 and 3HVR fingerprints revealed a complex pattern of restriction fragments, apparently refecting a multi-locus system of highly variable minisatellite alleles similar to the pattern of alleles reported in other vertebrates. The M13 fingerprints revealed a distinct pattern of restriction fragments of high molecular weight, reflecting a single-locus system that overlapped with the family of minisatellite alleles observed in 33.15 fingerprints. In a sample of 12 orange roughy collected on a single regional spawning site, the average percent similarity of 33.15 fingerprints was 21.15% (SD=17.75), the average percent similarity of 3HVR fingerprints was 14.32% (SD=14.45) and the inferred average allelic frequency of the M13 single-locus system was 0.071. A comparison of 33.15 and M13 fingerprints from two distant spawning sites ground New Zealand revealed no obvious regional differences. The variability of orange roughy fingerprints was so great, however, that regional comparisons could not be considered conclusive indicators of genetic identity. Our results provide a preliminary assessment of the power and pitfalls of using DNA-level markers for the population analysis of marine fish.