Apparently there are only 5 dugongs on exhibition anywhere in the world, and 2 of them are now at Sydney aquarium. There is a 10 year old male called Pig and a 4 year old female called Wuru, and they are in a 28 metre by 18 metre tank intended to replicate their natural habitat, which is the coastal waters in northern Australia.
You can find out more from this Sydney Morning Herald article.
