Just as clams, snails, and octopuses, squid are mollusks. The octopus has eight arms, and the squid does too but sports a long, cone-shaped body. The Pacific squid is the most common type of squid in Puget Sound. Because of its color, this animal is also called the "opalescent" squid, but the animal's color can change to match its surroundings or reflect its mood. A third name for this creature, "market" squid, comes from its popularity as human food.

The Pacific Squid is a skillful predator and eats small fish, crabs, shrimp, and also other mollusks, including young Pacific squid. In turn, bigger fish, birds, marine mammals, and people eat the squid.

At just a foot long, the Pacific squid is quite small, but its bigger relatives occasionally show up in Puget Sound. The Humboldt, or jumbo squid, can be almost six feet long. It used to be found only far south of Washington in warmer water. The even bigger Robust Clubhook squid has also appeared here.

All squid have several ways to avoid being eaten. They can blend into the background by almost instantly changing body color and pattern. They are jet-propelled and can zoom away suddenly, escaping enemies by expelling water from inside their bodies. And if these tricks don't work, squid eject clouds of ink to cloak themselves from view. The Pacific squid and its big relatives are definitely among Puget Sound's most amazing creatures.