It can't be worse than Megapiranha.
By the way, did anyone know that Sharktopus is actually the remake of an Italian (with french co-production) horror movie ("Shark: rosso nell'oceano", 1984)?
I know it's on wikipedia, I wrote the "original story" part on the Sharktopus page http://en.wikipedia.org/wiki/Sharktopus
. I loved that movie as a teenager. Late night gorefest.
The original monster looks more or less like a dinichthys with tentacles, and the guy who created it brags it has "the intelligence of a dolphin, the ferocity of a white shark, the strength of a giant octopus and the fearsomeness of a prehistoric creature". Plot written in white to avoid spoilers if you really mean to look for this masterpiece.Created as a biological weapon, the damn thing breaks free, eats a lot of people and the observation of its cells show that it's able to replicate itself asexually, meaning it would colonize the oceans and eat up everything in a few years. It's killed with FLAMETHROWERS.