Joe Dante’s Piranha (1978) is a cult aquatic horror classic produced by Roger Corman. When genetically altered piranhas are accidentally released into a river, a resort community becomes their feeding ground. Mixing sharp satire with gore and creature thrills, this fast-paced Jaws spoof became one of the defining monster movies of the late ’70s.

Från IMDB:
When flesh-eating piranhas are accidentally released into a summer resort's rivers, the guests become their next meal.