Market squid range from the southern tip of Baja California to southeastern Alaska, but are most common between Punta Eugenia in Baja California and Monterey Bay, California (NOAA). They spend most their time in the water column up to depths of 2,600 feet.
Market squid are active predators, commonly feeding on crustacea, fish, and even other juvenile market squid. They forage from the surface to the sea flooring and catch their prey with quick movements, grasping it in their arms. Market squid are an important food source for many predators, including larger fish, sea birds, marine mammals, and humans (Fields, 1962; Morris et al., 1980).
 

Market squid spawn in huge gatherings in the spring and fall, depending on the location. Males transfer spermatophores filled with sperm into the buccal cavity of the gravid female. One the eggs are fertilized, the female lays egg masses on sandy stretches of seafloor. Each egg mass consists of groups of eggs contained within a jelly capsule membrane (Fields, 1962). The eggs themselves contain a large ball of yolk surrounded by a transparent shell. The embryo begins formation through epiboly, where cells at the top of the yolk mass migrate around to the opposite pole, encapsulating the yolk with a layer of cells in the process (Brooks, 1880). The market squid, like other cephalopods, exhibits direct development and will hatch out as a miniaturized adult (Allen and Pernet, 2007).

Market squid are semelparous i.e. they reproduce only once before they die. This may occur because of the large energetic costs of producing gametes and from wounds incurred during the mating process itself (Fields, 1962).