PCR-based genetic identification of marlin and other billfish

Abstract

A genetic test was developed for the identification of the six species of billfish found in Australian waters (black marlin, Indo–Pacific blue marlin, striped marlin, Indo–Pacific sailfish, shortbill spearfish and broadbill swordfish). The test was based on the PCR–RFLP analysis of a 1400 bp region of the mitochondrial DNA molecule, the d-loop, using four restriction enzymes (Hinf I, Rsa I and Sau3A I andTaq I). A total of 33 composite haplotypes were observed among 160 fish; all were species-specific. Three of the species—black marlin, striped marlin and broadbill swordfish—showed sufficient intra-specific variation to be useful in population structure analyses.