Animal Species:Diamond Trevally, Alectis indica (Rüppell, 1830)

Adult Diamond Trevally have very angular dorsal and ventral profiles. Using a little imagination, the fish could be said to be diamond-shaped.

A Diamond Trevally caught at Rainbow Beach

A Diamond Trevally caught at Rainbow Beach
Photographer: Sharyn Gaunt © Sharyn Gaunt

Standard Common Name

Diamond Trevally

Alternative Name/s

Diamond-fish, High-brow Pennantfish, Indian Threadfish, Mirror-fish and Plumed Trevally.


The Diamond Trevally has a compressed body and a long straight snout. It has a large forked tail and long curved pectoral fins. The anterior section of the dorsal fin has long filaments in juveniles.

This species is silvery with a blue-green tinge above. Juveniles have five to seven broad, dark bands.

The Diamond Trevally looks similar to the Pennantfish. 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 Pennantfish. 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).

Size range

It grows to 1.5 m in length.


The Diamond Trevally occurs in tropical and warm temperate marine waters of the Indo-West Pacific.

In Australia it is known from south-western Western Australia, around the tropical north of the country and south to the central coast of New South Wales.

The map below shows the Australian distribution of the species based on public sightings and specimens in Australian Museums.  Source: Atlas of Living Australia.

Alectis indica

Distribution by collection data

Ozcam map of Diamond Trevally specimens in the Australian Museums.

What does this mean?



What does this mean?


  1. Allen, G.R. 1997. Marine Fishes of Tropical Australia and South-east Asia. Western Australian Museum. Pp. 292.
  2. Hutchins, B. & R. Swainston. 1986. Sea Fishes of Southern Australia. Complete Field Guide for Anglers and Divers. Swainston Publishing. Pp. 180.
  3. Kuiter, R.H. 2000. Coastal Fishes of South-eastern Australia. Gary Allen. Pp. 437.
  4. Randall, J.E., Allen, G.R. & R.C. Steene. 1997. Fishes of the Great Barrier Reef and Coral Sea. Crawford House Press. Pp. 557.
  5. Smith-Vaniz, W.F. in Carpenter, K.E. & V.H. Niem. 1999. The Living Marine Resources of the Western Central Pacific. Volume 4. Bony fishes part 2 (Mugilidae to Carangidae). FAO. Rome Pp. iii-v, 2069-2790.

Mark McGrouther , Collection Manager, Ichthyology
Last Updated:

Tags fishes, ichthyology, Diamond Trevally, Alectis indica, Carangidae, diamond-shaped body, Diamond-fish, High-brow Pennantfish, Indian Threadfish, Mirror-fish, Plumed Trevally, compressed body, silver, blue-green, juveniles have bands, angular shape, > 1m, tropical water, temperate water, marine,