Cephalpods like squids are fascinating creatures. They are extremely smart, can change color at will and look like something out of a 1950s science fiction movie come to life. Their most conspicuous feature is their tentacles, which have several interesting features.
Squid have two types of limbs, arms and tentacles. Most species have eight arms and two longer tentacles. There are exceptions, like the Caribbean reef squid, which have 10 arms. A squid's tentacles tend to be very muscular, and are evolved from the foot of mollusks like snails.
Suckers or Hooks?
Not all squids have suckers along their tentacles. Though squid and octopuses are known for their suckers, some squid have hooks instead of suckers. The Humboldt squid has a combination, suckers that have hooks concealed inside them. The colossal squid, the only squid larger than the giant squid, actually has rotating hooks and club-like ends on its tentacles.
All squids use their suckers and hooks for the same thing: hunting. All species of squids are predators, and feed exclusively on other animals. Squids use their tentacles to ensnare their prey. They use lightning fast movements to grab an animal and subdue it while they eat it. Depending on the squid, their diet includes crustaceans, fish and even other squids.
Using the Tentacles
Most squids catch their prey with very quick movements. The Humboldt squid, also known as the jumbo squid, can whip their feeding tentacles out in 20 milliseconds, which is almost faster than the human eye can see. The colossal squid holds its tentacles up around its head, which is called the "cockatoo position." From here, it can see its prey, and will shoot out two tentacles to grab it. They will then encircle the prey and hold it still enough to eat.