With a standard fishbowl, filtration simply isn't possible, and the fish will likely die.
"Unless the person performs very regular and frequent water changes, the concentrations of ammonia and nitrite can increase to toxic concentrations that could kill the fish," Bowser says, noting that fish also do best at normal room temperature.
Of course, there's also the question of whether goldfish in a bowl get sad or distressed living in such a small space.
"If the water quality is not optimal (e.g., high ammonia), I think they would be uncomfortable, and if the conditions were harsh enough, distressed," Lewbart says. "I think they are definitely capable of being distressed/stressed, uncomfortable, and, at some level, could suffer."