- Fish
- Crustaceans (such as shrimp, crabs, and lobsters)
- Mollusks (such as clams, mussels, and squid)
- Other cephalopods
- Plankton
- Seaweed
- Some species of cephalopods, such as the giant squid, are known to prey on even larger animals, such as seals and whales.
Cephalopods use their tentacles to capture and subdue their prey, and they have a beak that they use to crush the shells of mollusks and crustaceans. Some species of cephalopods, such as the octopus, also use venom to paralyze their prey.