Just when you thought it was safe: Dimension Films is already nibbling at “Piranha 3D — The Sequel.”

Mark Canton will again produce, although there is no word yet on who will helm the follow-up.

Alexandre Aja (“The Hills Have Eyes”) directed “Piranha 3D,” itself the latest in a series of pics that began with “Piranha” in 1978. Newest title opened over the weekend, logging $10 million for the frame.

Though the pic opened at only No. 6 among a clutch of new openers and strong holdovers, reviews were surprisingly toothy for the humor-laced fish tale.

“I’m delighted because the sequel is something we’ve clearly been talking about,” Canton said.

“With the really popular response of the audience, both here and in England, it has cemented our going to the script phase. We know it was a bifurcated weekend at the domestic box office, but we had the lowest drop of any film on Sunday night.”

“Piranha” launched day-and-date in the U.K. last weekend, where it grossed $2.3 million on 354 screens. The take is a healthy start for the scarer overseas, as the Weinstein Co. said it has secured distrib rights in all international markets.

Profile of “Piranha 3D” also has been boosted lately by a Funny or Die Web campaign to get the pic considered for an Oscar.

Dimension is the genre-oriented sibling of the Weinstein Co., which released docu “The Tillman Story” over the weekend. With the newly announced sequel, the “Piranha” property takes a step toward becoming a Dimension franchise along the lines of “Scream” and “Spy Kids,” both which have fourth installments under way.

Cast of “Piranha 3D” includes Elisabeth Shue, Jerry O’Connell, Ving Rhames, Richard Dreyfuss and Christopher Lloyd. Peter Goldfinger and Josh Stolberg penned the screenplay.