"Obsessed" co-star will fight fangy fish

First he had to deal with a killer co-worker; now it's toothy fish.

Jerry O'Connell, who co-starred in the thriller "Obsessed," has joined the cast of "Piranha 3D," sources say.

O'Connell joins an all-star cast including "Gossip Girl's" Jessica Szohr, Elisabeth Shue, Richard Dreyfuss, Ving Rhames, Adam Scott and Dina Meyer.

The story, based on a classic 1978 horror flick, follows a small-town Arizona sheriff (Shue) protecting her residents from an in-flux of prehistoric piranha. No word on what role O'Connell will play.

"Piranha 3D," currently in pre-production, has a tentative release date of 2010.