Squids are prominent members of the midwater community. Some swim weakly while other strong-swimming squids are part of the nekton.

The vampire squid looks something like an octopus but is neither a squid nor an octopus and is in its own separate group. Squids have light-emitting suckers. Vampire squids grow to about 12 in. Some species of vampire suids have photophores for bioluminescence.