So the government-funded “Razorteeth” project to assist with the Vietnam war was kind of a not-so-much. The plan was to dump a bunch of “super breed” piranha in North Vietnam swimming pools and let nature take its course. (All the had to do was give a bunch of little kids all the Kool-Aid™ they could drink, put ‘em in the waterways and let nature take its course. Problem solved.)
Two horny teens, out looking for a place to get their horn on, happen across a vacated military installation, and find a pool/fish hatchery. Off go the clothes, in go the appetizers. Have you ever seen a hot dog eating contest? The teens are the hot dogs and the genetically-engineered piranha are the contestants.
Later, when not so much as a crumb of the teens can’t be found, an insurance investigator happens across the compound, finds the pools drainage switch, and empties it…right into Lost River Lake, where a filled-to-capacity resort and summer camp waits for their turn on the hot plate. If you’ve seen Jaws (1975), you know it goes from here.
Menu items include summer camp kids, pets, and lakeside resort guests… The plan, though, isn’t to stop the piranha from eating anything that sticks its pink toes and fingers into the water, but rather to keep them from reaching the ocean. (Saved for Piranha II: The Spawning/1981.) That’s the military for you. Cut your losses, think outside the box, look at the big picture.
The piranha are only seen as toothy blurs, driven into voracious hunger frenzy by tasty floaters (think oyster crackers in tomato soup). When you do get to see one up close for a second, it looks like the chest-burster from Alien (1979). Same facial expression, anyway. They’re probably cousins. Elsewhere, some token female nudity, which is pretty much required in order to hold your interest in this one-punchline joke. I liked it, though. The female nudity, not the fish.