theres some yellow labs in the reptile room in one of the snake exhibits. theres also some scats, archerfish and tandanus cats in a lizard enclosure. something i don't understand is that there is good looking koi in the otter exhibit. they would get eaten!
the sydney aquarium is all australian native fish. not that aussie fish are bad, but, underwaterworld is better because they have a wide variety of freshwater fish from around the world.
edit: i got to go catch me one of those eels! theres some at a pond near my house