THE DART is a mainstay target species for anglers fishing along our surf beaches during the summer months. A number of species of dart can be caught around Australia’s coastline, all of which are amongst the smallest, but prettiest, members of the trevally family (Carangidae).
The largest of the dart species is the swallowtail dart, Trachinotus coppingeri, which grows to around 3kg and is frequently captured from the surf beaches and headlands along the east coast from the southern Great Barrier Reef to southern NSW, including Lord Howe Island. A close relative, the common dart (T. bolta) is found in similar locations on the northern parts of the Western Australian coast, while another northern relative, the small spotted dart (T. bailloni), which grows to around 60cm long, 1.5kg, and can be caught in coral lagoons in tropical waters and occasionally further south including northern NSW.
There is some uncertainty about the number of species of dart present in Australian waters, as all three species listed above are very similar in appearance to those that occur overseas in the Indian and Pacific oceans. Most of the differences used to distinguish these species are very slight, such as the length and position of their prominent backswept dorsal and anal fins, shape of the head and tail, and body markings such as the size, position and colour of the prominent spots along their lateral line.
The uncertainty exists because some of these features can vary with the size of the fish. For example, in swallowtail dart the number of spots along the lateral line tends to increase with the size of the fish. Juvenile swallowtail dart usually have only three or four light coloured spots on their flanks, while large adults can have up to sic or seven. In contrast, even large adults of the black spotted dart only have four or five spots, with these being smaller and darker than those found on swallowtail dart.
In contrast, all three of the local species are easy to distinguish from their esteemed larger cousin the Aussie permit, or snub nosed dart (Trachinotus blochii) by virtue of their different head shapes, thinner bodies and dark (as opposed to yellow) dorsal and anal fins (not to mention their smaller size).
Other closely related species include queenfish, which like dart have a very compressed body plan which gives them broad sides but a narrow frontal profile. These traits that dart share with their larger cousins provide them with considerable ability as dogged fighters. Indeed, they provide opposition far outweighing their size, especially in the surf where swallowtail dart in particular use the surging waves and deep bodies to maximum advantage.
Food items for dart mainly include a wide variety of molluscs, polychaete worms and crustaceans, but also small fish, as indicated by their avid taking of small chrome and soft plastic lures.
In Queensland tagging studies have shown that most swallowtail dart are recaptured less than 4 km from their release site, however, movements of up to 275 km were recorded for mainly larger fish. Relatively little is known about spawning, growth rates and size at first maturity for our dart species, however, in SE Queensland swallowtail dart spawn in summer between October and April, and that this species matures at around 26 cm fork length, suggesting that a reasonably large minimum size would be needed to adequately protect dart populations exposed to heavy fishing pressure. Swallowtail dart have been recorded to around 3 kg in weight, which makes for an exceptional fish.
