Life Cycle: -Life span is for about 4-5 years. -There are three main periods in the zebra mussel life cycle: the larval, juvenile, and adult stages. -The larvae are planktonic (float in water column) during their initial three life stages: trochophore, straight-hinged veliger, and umbonal veliger. Larvae eventually settle on a substrate during their pediveliger stage, and move only by crawling during their plantigrade stage. -Mussels are considered adults when they become sexually mature. Adult mussels range from approximately 6 to 45 mm and generally live to be 2-3 years old in temperate climates.