Pest fish Tilapia found in the Mary River near Tiaro

A fish caught recently in the Mary River near Tiaro was positively identified as the pest fish Tilapia (Oreochromis mossambicus). 

A further investigation of the Tiaro reach of the river by MRCCC’s Chris Rosin and Chris Mangold discovered hundreds of Tilapia in the Mary River.  Tilapia are in the top 100 worst introduced species in the world, and are a massive threat to Australia’s aquatic biodiversity.

This is a hardy fish, tolerant of poor water quality and with the ability to survive even in brackish water.  Tilapia are mouth brooders – the female carries eggs and larvae in her mouth.  They have been described as the fish equivalent of the Cane Toad.  Efforts are now being increased to find out where else Tilapia may be in the Mary River system.

Tilapia can be relatively easily identified by the continuous dorsal fin along its spine (most native fish have a break or dip in their dorsal fin).  Click on the link below for images of Tilapia showing the unbroken dorsal fin and the various colourations of the species.

If you catch a Tilapia, do not release it back into the river, or keep it for bait, or leave it on the river banks.  Any Tilapia caught should be appropriately disposed of, and please notify MRCCC or Boating and Fisheries on 13 25 23.

Tilapia images


For more information, visit






One of the world's top 100 worst pest species

One of the world’s top 100 worst pest species