The basic cephalopod body plan includes two eyes, a mantle, a funnel (also called a siphon), and at least eight arms. Cephalopods have long fascinated humans and were frequently mentioned by Aristotle, and this fascination shows no signs of diminishing today.Īnatomy, Diversity, and Evolution AnatomyĬephalopod literally means “head foot” in Greek, a reference to the way the cephalopod’s head connects to its many arms. The largest-the giant squid-measures longer than a school bus, while the smallest ones-like the pygmy squid and California lilliput octopus-could sit on the tip of your finger. Early in their evolution, cephalopods relied on the sturdy protection of shells, but over time many eventually lost the outer shell and instead relied on new adaptations like heightened intelligence, a talent for hiding, and strong, flexible arms.
A highly intelligent group of ocean dwelling creatures, the living cephalopods include the eight-armed octopuses, the ten-armed squids and cuttlefishes, and the shelled chambered nautiluses.
