Barramundi, Lates calcarifer (Bloch, 1790)

Introduction

The Barramundi is one of Australia's most well known freshwater species. It is prized by recreational anglers because it is a strong fighter, grows to a large size (60 kg) and is an excellent table fish. It is also the most important freshwater commercial fish in Australia. The Barramundi can be recognised by its pointed head, concave forehead, large jaw extending behind the eye and rounded caudal fin.

Identification

The Barramundi can be recognised by its pointed head, concave forehead, large jaw extending behind the eye and rounded caudal fin. It has a first dorsal fin with seven or eight strong spines and an second soft-rayed dorsal fin of ten or eleven rays.

Adult Barramundi are blue to green-grey dorsally, silvery on the sides, and white below. Juveniles are mottled brown with a distinct white stripe from the dorsal fin to the snout.

The Barramundi closely resembles the Nile Perch, Lates niloticus, an African freshwater species that is imported from Tanzania, Kenya and Uganda. The two species are difficult to tell apart because the body proportions change with growth. Only two characters are useful. The number of lateral line scales (Barramundi, 52-61 vs Nile Perch, 60-80) and width of the bony interorbital as a percentage of standard length. (Barramundi, 3.2% to 3.6% vs Nile Perch, 4.1% to 4.9%). The latter figures are from an unpublished report produced in 1990 by John Paxton.

Habitat

It lives in a range of conditions in creeks, rivers and estuaries in clear to turbid waters.

Distribution

The species has been recorded from the Persian Gulf to China and south through Asia to Australia.

In Australia it occurs from the Kimberley and Pilbara regions of Western Australia and around the north of the country to the Mary and Maroochy River systems in southern Queensland.

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

Feeding and diet

The Barramundi eats a range of foods including fishes, shrimps, crayfish, crabs and aquatic insects.

Breeding behaviours

Young fish live in the upper reaches of freshwaters. As they mature they move to estuaries often near mangroves. Breeding occurs in estuaries and coastal shallows. Males over five years of age usually go through a sex transformation to become female (they are protandrous hermaphrodites). Sexual maturity for males occurs at 3 to 4 years of age. Not all males become females.

Economic impacts

It is the most important freshwater commercial fish in Australia.

References

1. Allen, G.R. 1989. Freshwater Fishes of Australia. T.F.H. Publications. Pp. 240.
2. Allen, G.R., Midgley, S.H. & M. Allen. 2002. Field Guide to the Freshwater Fishes of Australia. Western Australian Museum. Pp. 394.
3. Merrick, J.R. & G.E. Schmida. 1984. Australian Freshwater Fishes. Biology and Management. John R. Merrick. Pp. 409.
4. Yearsley, G.K., Last, P.R. & R.D. Ward. 2003. Australian Seafood Handbook, an identification guide to imported species. CSIRO Marine Research. Pp. 231.