If it is the fish I am thinking of, the singing gourami (T. pumilus) is hardy ONLY if you meet their water conditions.
They used to be rare. I am sure by now the small size has tempted someone to breed them commercially. Or maybe make a small hybrid with the hardier regular croakers. I haven't found a easy source yet.
They are wonderful little fish, quite shy and you have to be careful of tankmates.. they do best in a species tank or with very gentle amusing tankmates like cories or striata botia or you will never hear them sing and rarely see them out of hiding. They can be housed in small social groups and can interbreed with regular size croakers. AS most bubble nesters, do show aggressive tendencies at breeding time and while establishing pecking order. So you need 4 or any uneven number over 4.
And if unhappy/ill they are simply drab little brown fish. And they do bully similar fish and do most labyrinths. As all 3 croakers, they have the striking blue eyes.
You won't see them in most fish stores because the water needs. A store that carries them will have many softwater specialty fish I bet. (Like chocolats and liqourice gourami or actually raising discus).
They DEFINITELY take their coffee black! The water needs to be under 7pH and quite acidic. They also get nervous if the water is too clear or not planted enough.
If the water is good, they NEVER get sick and get in the mood a lot.
I love my little vittatus croakers but wish I could get the singing, they have sweeter sound effects.
You should search arouund with the word sale
and their scientific name and see if you find them.
I am ordering wild caught through my lfs
becuase I wish to become active in species maintainence and I want a pure strain.