Why are tentacles and arms different

11 What's the difference between an arm and a tentacle? Arms, like those on an octopus, have suction cups the entire length of the limb. 29 thg 8, Octopus tentacles still react up to an hour after being severed from their Other research found that, when encountering a piece of food. 30 thg 4, The cup-shaped sucker connects to the squid arm or tentacle via a thin Octopus, squid, cuttlefish, and nautilus all have differently.