Taylor Dean is a 19-year-old from San Antonio who currently makes her living creating educational animal videos on YouTube. Her friend, Derek, 20, works at a local aquarium shop in the same city.
Dean said a customer of Derek's recently brought in their pet goldfish that was suffering from swim bladder disease, a disorder that prevents a goldfish from controlling its buoyancy in the water.
The swim bladder is essentially an organ helps the fish stay stable in water. When the bladder is deformed or affected/infected — by bacteria or parasites, for example — the goldfish loses its floatation stability. This can cause it to float to the top of the water, swim upside-down, or have a heavy lean toward one side.
According to Derek, this particular goldfish had an incurable swim bladder problem that prevented it from holding itself upright, and made it permanently stuck at the bottom of its tank.