Pennantfish
Juvenile Pennantfish have very elongate trailing filaments from the dorsal and anal fins. These are not present in adults.
The species grows to about 1.3 m in length.
It is a pelagic species that lives in inshore and continental shelf waters from the surface to about 100 m.
The Pennantfish occurs circumglobally in tropical and some temperate waters
In Australia it is known from south-western Western Australia, around the tropical north of the country to the southern coast of New South Wales.
The Diamond Trevally is also known as the Diamond-fish, High-brow Pennantfish, Indian Threadfish, Mirror-fish and Plumed Trevally.
The Diamond Trevally looks similar to the Pennant Fish Alectis ciliaris. It can be distinguished by the more angular shape of the head and nape versus a more rounded head, respectively. The distance between the eye and upper jaw (suborbital depth) is contained 0.8 to 1 times in the upper jaw length of the Diamond Trevally compared with 1.7 to 3 times in the Pennant Fish. There are also differences in the number of gill rakers on the lower limb of the first gill arch (21 to 26 versus 12 to 17).