Molecular tools using DNA sequencing can improve pest fish management by ensuring accurate identification of fish, especially larval fish, without the need for specialist taxonomic knowledge. DNA is made of four chemicals; guanine (G), adenine (A), thymine (T), or cytosine (C), joined together as a string (Figure 1). The order of the chemicals is unique to each species and can be used as a DNA "barcode" to identify organisms. It is relatively simple to obtain DNA sequences for a reference gene such as the widely accepted "barcode gene" cytochrome C oxidase subunit 1, and compare the sequence to a voucher specimen sequence in genetic databases such as GenBank and the Barcode of Life database BOLD.