Cichlids (in general) are not brackish fish....african cichlids commonly have cichlid salts added to their water but it isn't the same formula as marine salt. SA cichlids that live in rivers may on occasion go into the mouth of the river but they are thought to go there because they have parasites that cannot withstand the change of chemistry or because the fish wants to migrate to another river. There is a cichlid that lives almost exclusively in salt/brackish conditions but I have forgotten the name and the fish in the pics is not it.....
About a year or so ago, in FAMA magazine was an article about this guy who wanted to put freshwater cichlids into a salt tank. I don't know why he wanted to do this as let's face it, they aren't that great looking compared to salt. I guess he just had to prove something. To make a long story short, he ended up killing a couple of dozen fish trying this before he ended up with one fish that managed to live through the process. The fish lived for a couple of years then he tired of it and tried to sell it to a LFS. None of them wanted it...go figure....who would want a saltwater cichlid???
Oh, and he had pics of various types of cichlids that he tried...took them before they died and they looked like crap. Midas cichlids all washed out....convicts cowering in the corners....jack dempseys pale as can be......
IMO I think it is cruel. Like taking a saltwater fish and forcing it to live in fresh. Sure it may survive for a time but it will live a much shortened life. The only reason the cichlid may live longer is that like most freshwater fish they are used to some change in their environment so their ability to adapt is greater. If you were to put the fish back into freshwater, you will have to do a very slow change. It will take days to do this and even then it may still die from the shock.
Ah, remembered the name of the cichlid that lives in brackish/salt water. Orange chromide.