Any marine mollusk of the class Cephalopoda (e.g., cuttlefish, nautilus, octopus, and squid), which includes the most active and largest living invertebrates. Cephalopods are bilaterally symmetrical and typically have a highly developed centralized nervous system. Their image-forming eyes are similar in structure to vertebrate eyes, and their heads are armed with tentacles that have rows of round suction disks. Most cephalopods can change skin colour to blend in with their surroundings. All can swim, propelling themselves backward by expelling water forcefully. Most are carnivores that feed on fish, crustaceans, and other mollusks.

This entry comes from Encyclopædia Britannica Concise.
For the full entry on cephalopod, visit Britannica.com.

Seen & Heard

What made you look up cephalopod? Please tell us what you were reading, watching or discussing that led you here.

Get Our Free Apps
Voice Search, Favorites,
Word of the Day, and More
Join Us on FB & Twitter
Get the Word of the Day and More