Killer Fish
In this violent, low-budget adventure, a jewel thief hides his loot in the bottom of a Brazilian lake filled with hungry piranhas. Later his avaricious gang members try to retrieve the treasure but unfortunately tend to get graphically devoured each time one of them enters the water. Putting the rocks down there seemed like such a good idea at the time!
Director: Antonio Margheriti
Starring: Lee Majors, Karen Black, James Franciscus, Margaux Hemingway, Marisa Berenson