Final answer:
Squids and octopuses use jet propulsion to move quickly away from predators, ejecting water from their mantle cavity. Octopuses can also release an ink cloud to hinder predators' sight, aiding their escape. Additionally, they can change color and texture for camouflage.
Step-by-step explanation:
Squids and octopuses move quickly away from predators by using jet propulsion. This is achieved by contracting their mantle cavity to forcefully eject a stream of water, propelling them rapidly in the opposite direction. An octopus has the additional defensive mechanism of releasing an ink-like substance to obscure the view of predators, allowing for a quicker escape. This ink cloud can act as a smokescreen or create a decoy to distract predators. For squids, this mode of locomotion is so effective that they can reach speeds of 8 to 12 km/h. These cephalopods are also capable of changing their color and texture for camouflage, which is a secondary means of evading predators if necessary.