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Generalized life cycle of the cockle: Cockles are hermaphroditic. Spawning may extend over several months, but peak spawning occurs in May-September in south coast area. Mass fertilization occurs in water column. Fertilized eggs develop rapidly into ciliated, motile larvae. Larvae phase includes several stages (i.e. trochophore, veliger and umbone), during which time the larvae drift in the plankton and are dispersed by water currents. The larvae phase ends when larvae settle from the plankton and attach themselves to gravel or broken shell in sublittoral zone. Juvenile clam then burrows into substrate. As juvenile cockle grows it moves inshore and into intertidal. Adults usually live to a maximum age of 7 years and shell length may reach 12 cm.