Gopu, also known as longtail tuna, can reach 1.5 metres in length and 32 kg in weight. Although often mistaken for bluefin tuna, these large fish are more streamlined, particularly towards the rear of the body. Preferring tropical waters, these fish are nonetheless widely found; their habitat in summer extends from Western Australia to Eden in the southeast of NSW. 

Capable of incredible power, gopu is an extremely  adept hunter. It is not uncommon to see a massive, fully-grown longtail pursue a garfish or other smaller prey right up into shallow or surface water.