A quick google search produced this
Six native fish species live in the freshwater section of Wolli Creek and can sometimes be seen above the Henderson Street weir. These are: Empire Gudgeon (Hypseleotris compressa), Flathead Gudgeon (Philypnodon grandiceps), Striped Gudgeon (Gobiomorphus australis), Firetail Gudgeon (Hypseleotris galii), Common Galaxia (Galaxis maculatus) and Long-Finned Eel (Anguilla reinhardtii).
Cheers
Rah