Unlike nautilus and snails, the octopus and squid evolved to have bodies that don’t require use of a hard shell for protection, which is due to other adaptations that they developed like the ability to camouflage, heightened intelligence, and strong, flexible arms. These animals are all characterized by symmetrical bodies, no vertebrae, prominent heads, and arms or tentacles that extend from their bodies. The largest cephalopod is the giant squid and the smallest being the pygmy squid. They are cousins-both part of the group cephalopoda -a group of marine mollusks that include squid, octopus, nautilus, and snails. You wouldn’t be alone if you thought the octopus and squid were the same animals.
Squid – NOAA OKEANOS Explorer Program 2013 Northeast U. Photo credits: Octopus – NURC/UNCW and NOAA/FGBNMS.
