Freshwater lionfish/stonefish?

[Diagsith]

Hey guys, a friend of mine picked up a interesting fish a few months ago, but for all this time we could never find any info on it.
it was marketed as a "Freshwater Lionfish" but to me he looks like some kind of stonefish.
So far he's lived by himself in a 20 gallon and eats the occasional guppy that wanders by.
Can anyone tell me what kind of fish he is/water conditions/ temp/ max size/ preferred diet? any info would be of help.

Heres a pic of him chillin at the bottom.

A'int he a beaut?

 

[CFC]

Batrachus grunniens is a brackish/marine dwelling fish that only enters freshwater to spawn, the young fish hang about in freshwater until they are juviniles and then move out into saltier water to join the adult fish, if kept in freshwater for the long term the fishes health will suffer and it will die. They should be kept in a brackish tank with a SG of at least 1.010 or a full marine tank.
They should grow to around 8 inches and are strict carnivors eating smaller fish, shrimps and other crustaceans that wander past their huge mouths.
The dorsal spine of this fish contains a venom gland which can deliver a painful sting if handled.

 

[Eve]

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[Clare]

We had 3 of these and lost 2. They simply would not eat. The third however, eats realy well taking whitebait and earthworms.
Need to be in brackish water and have you heard them grunt when they are upset over something? They are really loud and it`s quite a strange noise.

Not a fish I would keep again, gorgeous and marvellous to watch, but one that I personally feel doesn`t take to captivity well.
Good luck though

 

[Diagsith]

thanks for the info