Slamfire
Contributor
This may have been posted here before since the video is 2yrs old. Nonetheless I think there may be some people out there that, like me, have not seen this until today. It happened at the Seattle Aquarium and the Sharks are actually dogfish. Yes, believe it or not, dogfish are considered sharks too. An older lower res video of the same incident mentioned that these were 3' to 4' dogfish.
YouTube - Shark vs Octopus
YouTube - Shark vs Octopus