From the NY Times:
''The law is strict on the permitted uses of piranha fish,'' said Charles Guthrie, acting regional fisheries manager for the state's Department of Environmental Conservation. ''Piranha can be possessed with a permit for scientific or biological purposes, or for public exhibition.''
The state will not issue a piranha permit to a person wanting a piranha for the parlor. ''We don't issue to private individuals,'' Mr. Guthrie said. ''These fish are potentially dangerous. They have teeth, they bite. You get a school of them together in the wild and they could do some damage.''