This common octopus (Octopus vulgaris) doesn't have a jetpack to help him zoom through the water, but he's got something pretty close: a funnel that shoots water. (It's the little orange/yellow cup in the picture.) Octopuses pull water into their mantle cavities and then squeeze it out through the siphon (also called a funnel) at the front of their mantles to both swim and steer.