are american flagfish brackish water

[sun catfish]

i saw some really cute flagfish in the fish store to day and i wanted to know if they are brackish or could be kept in brackish at all. i have a at least 1 1/2 inch bumble bee goby and the flagfish in the store where like 1/2 a inch long. please help me

 

[Cichlaholics Anonymous]

they can be kept in lower end brackish water, specific gravity lower than 1.010