Fisherman Matt Boyd is fishing in Lake Victoria when a small earthquake hits, splitting the lake floor and causing a whirlpool. Boyd falls in and is ripped apart by a school of piranhas that emerge from the chasm.As spring break begins, Jake Forester reunites with his old crush Kelly and meets her arrogant boyfriend, Todd Dupree. Jake meets Derrick Jones, a sleazy pornographer as well as Danni, one of his actresses. Derrick convinces Jake to show him good spots on the lake for filming a pornographic movie. Jake’s mother, Sheriff Julie Forester, searches for the missing Matt Boyd with Deputy Fallon. They find his mutilated body and contemplate closing the lake. However, this decision is made difficult with thousands of partying college students on spring break, which is important for bringing revenue to the small town. The next morning, a lone cliff diver is attacked and consumed by the vicious piranhas.Piranha 3D 2010,
Jake’s siblings Zane and Laura take a canoe to go fishing on a small sandbar island and become stranded in the middle of the lake due to Zane neglecting to properly secure the canoe. Jake runs into Kelly, who accepted Derrick’s invitation on board his boat, and meets Derrick’s other actress Crystal and his cameraman Andrew.
Julie takes a team of seismologist divers: Novak, Sam, and Paula to the fissure. Novak speculates that the rift leads to a buried prehistoric lake. Paula and Sam scuba dive to the bottom and discover a big cavern filled with large piranha egg stocks. Both are killed by the piranhas before they can alert the others. Novak and Julie find Paula’s corpse and pull it onto the boat, capturing a lone piranha, which they take to Carl Goodman, a retired marine biologist. He explains that it is a highly aggressive prehistoric species known as Pygocentrus nattereri, or the Original Piranha, long believed to have been extinct for over 2 million years and that the piranhas have survived through cannibalism. The species is able to vigorously devour its prey in seconds.