My 4 year old son was given an aquarium and two goldfish for his birthday. A week later, we noticed that one of the goldfish was not looking right...bloated (moreso than it had looked). The following day we noticed bumps, and thread like extensions coming off of it on its body. I had not looked at the fish so closely before, but after some research found that it had anchor worms. This came from the aquarium it was in! These were bought at Petco. I am so upset over this and with Petco. I would HIGHLY discourage anyone from purchasing fish from Petco because of this.