The market squid is probably the most abundant cephalopod along the central coast of California. These iridescent animals migrate in huge schools from Mexico to southeastern Alaska and are fished commercially. Market squid grow quickly and live to be about a year old.
When spawning, thousands of squid swarm into shallow waters—such as those of Monterey Bay. After the males deposit sperm packets into the females, the females lay many cylindrical capsules, each containing 180 to 300 eggs. After mating, the adults die.
Until recently, market squid supported the largest fishery in Monterey Bay (by tonnage). By 1996, the sardine fishery far surpassed it. What caused this change in the squid fishery? We don't know for sure.
In the spring and fall, market squid enter Monterey Bay in huge schools to spawn. They deposit their eggs on shallow mud flats and the sandy seafloor, then die.