Giant Trevally - Taxonomy and Phylogeny

Taxonomy and Phylogeny

The giant trevally is classified within the genus Caranx, one of a number of groups known as the jacks or trevallies. Caranx itself is part of the larger jack and horse mackerel family Carangidae, a group of percoid fishes in the order Perciformes.

The giant trevally was first scientifically described by the Swedish naturalist Peter Forsskål in 1775 based on specimens taken from the Red Sea off both Yemen and Saudi Arabia, with one of these designated to be the holotype. He named the species Scomber ignobilis, with the specific epithet Latin for "unknown", "obscure" or "ignoble". It was assigned to the mackerel genus Scomber, where many carangids were placed before they were classified as a separate family. This later revision in classification saw the species moved to the genus Caranx, where it has remained. Even after its initial description, the giant trevally (and the bigeye trevally) were often confused with the Atlantic crevalle jack, Caranx hippos, due to their superficial similarity, which led to some authors claiming the crevalle jack had a circumtropical distribution. After Forsskål's initial description and naming, the species was independently renamed three times as Caranx lessonii, Caranx ekala and Carangus hippoides, all of which are now considered invalid junior synonyms. The latter of these names once again highlighted the similarity with the crevalle jack, with the epithet hippoides essentially meaning "like Carangus hippos", which was the crevalle jack's Latin name at that time. Despite the resemblance with the crevalle jack, the two species have never been phylogenetically compared, either morphologically or genetically, to determine their relationship.

C. ignobilis is most commonly referred to as the giant trevally (or giant kingfish) due to its large maximum size, with this often abbreviated to simply GT by many anglers. Other names occasionally used include lowly trevally, barrier trevally, yellowfin jack (not to be confused with Hemicaranx leucurus), Forsskål's Indo-Pacific jack fish and Goyan fish. In Hawaii, the species is almost exclusively referred to as ulua, often in conjunction with the prefixes black, white, or giant. Due to its wide distribution, many other names for the species in different languages are also used.