Common Pufferfish

One of the few freshwater puffers, the common pufferfish has a rotund body, attractively colored with green and patches of yellow. When threatened, it inflates its body with water until it is virtually globular, but it does not have skin spines. With its plump, rather rigid, body the puffer moves slowly, using undulations of its small dorsal and anal fins, but it compensates for this lack of speed by its defensive techniques. It feeds on bottom-dwelling invertebrates and on fish.  Common puffers are very popular aquarium fishes and have been bred in captivity. The female sheds her eggs on the bottom, where they are guarded by the male, who lies over them until they hatch.  Many members of the puffer family are considered good food fish, despite the fact that their internal organs -- and occasionally even the flesh -- are extremely toxic and can cause fatal poisoning. In Japan, chefs are specially trained in the cooking of puffers, known as fugu, but there are still a number of cases of poisoning.