Why do octopuses take off their wrists to escape at a critical moment?

Octopus sucks water into the mantle, breathes it and excretes it through a short funnel-shaped tube. Octopus mostly crawls on the seabed with suction cups, but when it is frightened, it will spray water from the body tube, and the sprayed water flow is strong, thus moving quickly in the opposite direction. In case of danger, ink-like substances will be sprayed out as a smoke screen. Some substances can paralyze the attacker's sensory organs.