I am not 100% sure but if they are tank breed then they can take 77 - 78 degrees. But you never can tell where the fish came from. My friend has one of these in a nano that he has had for 3 months now and it seems to be doing fine he keeps the tank at about 77-78. I am sure that it would probably live longer and happier if the temp was lower. I guess we will see what happens.