Nope. Fish are happy in aquariums! As long as the tank is sized for the fish adequately, and not too crowded, and has nice rocks or sculptures and hiding places and plants, and reasonably clean water and quality food, the fish will be happy. read more
For example, fish that live in groups but are placed in tanks alone can be very stressed, because in the wild being isolated means being in great danger of being eaten. Fish in aquariums without suitable cover may become very stressed, for more or less the same reason. read more