Most people know them as calamari, the ubiquitous appetizers on most restaurant menus, but their real name is common market squid (Loligo opalescens). They are members of the mollusk family known as cephalopods, which means foot-on-head. They have eight arms and two tentacles that extend from the ends of their bodies where their mouths are present, and swim tail first by pumping water through valves near their heads. These jet-propelled creatures wander the eastern Pacific from the waters off southeastern Alaska to Mexico in enormous schools. Market squid grow fast, live only twelve or fourteen months, and depending upon oceanographic conditions, their populations fluctuate quite a bit from year to year. They range in length from three to seven inches, including their tentacles. Market squid and their relatives in the oceans around the world are critical sources of protein not only for restaurant patrons, but just about everything that swims in the sea. They are fished commercially with seines, lampara nets, and trawls, and for sport with fluorescent jigs.