The skipjack trevally is a streamlined, fast-swimming, schooling species within the family Carangidae, which contains about 140 species, mainly restricted to the tropics. It has a reflective silverfish-green body with a black spot on the margin of the operculum and a deeply forked tail. Juveniles have a yellow stripe present along the midline and six or seven broad pale vertical bands on the sides. The skipjack trevally grows to a maximum length of 94 centimetres.
Juvenile skipjack trevally usually inhabit estuaries, bays and shallow continental shelf waters, while adults occur in large schools near the sea floor in coastal waters and occasionally enters deep estuaries to depths of 120 metres. Adults also live on inshore reefs and over open grounds of sand or gravel in large bays and inlets. This species are carnivorous benthic feeders and feed on polychaete worms, molluscs and crustaceans such as amphipods. Pelagic schools of skipjack trevally are known to feed on planktonic crustaceans such as krill. Skipjack trevally spawn in summer. They have been found spawning in both estuaries and shelf waters. They appear to be serial spawners, releasing several batches of eggs over a number of weeks. The eggs are planktonic and are about 0.8mm in diameter. They range from the North West Cape, WA to southern QLD and around Tasmania. Skipjack trevally are also widely distributed in warm temperate waters worldwide
Other common names include: Silver trevally, white trevally, skippy, trevally, and blurter.
Occurrence at the Busselton Jetty:
Skipjack trevally are a common schooling species that are observed on a daily basis from the underwater observatory. They form small to moderate sized aggregations, swimming from the open water zone through to the seafloor. They are often observed feeding on the seafloor, sifting through the sediment for benthic invertebrates. Large mature adults are not often seen, the majority reach a maximum of approximately 40 centimetres.
Image by: O.Rynvis