Whitsunday Giant Trevally

Giant Trevally in the Whitsundays

The GT is robust and solid in appearance and can be recognised by a steep and blunt head profile. They have immense power which can be attributed to thick shoulders and midsections of muscle and large almost paddle like pectoral and tail fins.

Giant Trevally are a huge and powerful fish. They are an aggressive predator and will hunt anything smaller than themselves. They have powerful forebodies and plenty of muscles leading to a paddle like pectoral and tail fins. Generally here in the Whitsundays, they are a silver colour, though darker colors are sometimes found and other fish such as the Big Eye Trelavvy can be almost black in color.

Towards the tail, the Giat Trevally has a series of Scutes (small sharp blade like plates) along the lateral line leading towards the base of the tail. Sometimes fishermen can get quite deep lacerations trying to land a GT by it's tail without using gloves.

Distribution & Habitat

GT are widespread throughout the world, from the warm tropical waters of the Pacific and Indian Oceans. They are usually found as far south as central New South Wales (Australia), east to the Hawaiian Islands, west to the eastern islands of Africa and north to Japan.

Theirlive in almost every habitat from estuaries to coral reef systems. Juvenile Giant Trevally are more likely to be found in the estuaries, rockwalls and river systems in the Whitsundays while the larger fish will be out in deeper water along the drop offs and ledges of coral reefs. Strong currents caused by tidal ranges of up to 4m are common where these deepwater environments exist and they'll often be found sitting in the pressure wave using minimal effort while they wait for a passing feed. As the tide rises, they will also venture onto sandflats, mudflats, into mangrove systems and along the top of coral reefs to hunt. GTs can also be found along the reef edge and points where large pounding swells crash on the reef and rock stirring up food and creating the ideal environment to hunt.

Size & Age

Giant Trevally are sexually mature in the first 3-4 years of age and are generally around 60cm in length. The GT is a very fast growing fish. Large, usually solitary specimens can reach almost 2m in length. These larger specimens seem to be fairly territorial and it is debated whether the fish strikes a popper or lure mistaking food or attacking it as an intruder.

Feeding

The GT is a spectacular striker when taking a bait or lure. This fish usually takes a whole bait or lure in one strike. If it misses the first hit, it usually heads back for a seconds strike, very quickly before it looses it's meal to a nearby competitor. They particularly like Yellowtailes Fusiliers. Taking one of these off a nearby reef, with a single hook through the back and casting it into a fast flowing tide around a deep drop off is often more than the GT can resist and strikes happen almost instantly.