Winter flounder or "blackbacks" live 15 to 18 years and grow up to over 2 feet in length. They spawn during the winter and spring in shallow inshore waters, often returning to the same areas where they were born to spawn. Females usually produce between 500,000 and 1.5 million eggs. They deposit their eggs on sandy bottoms and algal mats at night, usually about 40 times every spawning season. Newly hatched larvae have one eye on each side of the head. Five to six weeks after they hatch, larvae settle to the bottom to begin their transformation into juveniles. After weeks of adapting to living on the bottom, their left eye migrates to the right side of their body and their metamorphosis is complete. The growth and survival rates of larvae and juveniles depend on several factors, including temperature, salinity, water quality, and the availability of food.