There are two species of freshwater shark in top end rivers. One is
called Bull Shark and the other is the Speeartooth Shark. I have had 90
sm Bull Sharks in an aquarium but they are crazy and do not settle. I
have also seen bullsharks swimming among Western Rainbowfish here in the
Blackmore River which runs into Darwin Harbour. We also have Freshwater
whiprays which grow to a disc diameter 3 meters and 640 kg. Imagine the
size of the community aquarium. How big is your hobby budget?