Gopu, also called black marlin, can be found in tropical and sub-tropical waters of the Indian and Pacific oceans, and can grow to  a maximum length of 4.6 metres and weigh 750 kg. Marlin is amongst the fastest fish known in the world, reaching phenomenal speeds of up to 35 km/h. Compared to their striped marlin cousins, black marlins have shorter bills and are rotund - so much so, that sometimes their pectoral fins no longer sit flush to their bodies.

Males will live for five years, but a female gopu can live for 12 years, spawning up to 40 million eggs at one time. Gopu can be found off the coast, at depths of up to 900 metres.