This is what everyone who fishes the Colo seems to be chasing, Australian Bass (Macquaria novemaculeata). You can find out more about the Australian Bass here. Bass can be caught from the mouth of the Colo all the way up to the junction with Bob Turner’s track and beyond.
Fisherman also seem to catch Murray River turtles quite commonly on the Colo as well. The largest fish I have landed on the Colo was 120cms long (sorry no photos, but I can supply witnesses) and was located approximately half way between the Upper Colo Bridge and the Putty Bridge.