theonetruepath said:Looks very much like the Desert Goby, Chlamydogobius eremius.
Occurs in the middle of Australia, around Lake Eyre and the Flinders ranges.
Max size 6cm.
Apparently it can handle temps of 5 to 41 degrees C (!), salinity of 0 to 60 parts per thousand (!!), PH of 6.8 to 11.0 (!!!) and even very low oxygen levels.
Seems if you want to kill it you're going to have to hit it very hard with a brick.