It is a freshwater/brackishwater fish. I have it in freshwater and there are no problems at all. I presume it inhabits freshwater and/or possibly esturies.
It is a preditory fish which waits for the prey to get within striking distance. It hunts them down and then waits for the right moment.
It has eaten a 3-4" rainbow cichlid whole in the past. I had hoped it might co-inhabit the tank with it as it seemed a little large for a meal.....the goby proved otherwise!
I tend to feed it mainly on prawn, white bait and worms, although it does have the occasional runt.