When flounders are born, they are bilaterally symmetrical like most fishes, with an eye on each side. However, after several weeks (depending on temperature and species) something very unusual occurs. They start to lean to one side, and the eye on that side begins to migrate to what will become the top side of the fish. Because of this, many other complicated changes occur in their bones, nerves, and muscles. The underside of the flounder loses its colour. Adult flounders live on the bottom of the ocean with the eyed side facing upward. Female flounders grow faster and larger than the males.
Winter flounders(Pseudopteuronectes americanus): Winter flounders is one of the best known inshore marine fishes. They take the form of a mature flatfish after 2.5-3.5 months. They usually grow to an average size of 25 inches in length and about 8 lbs in weight, reaching sexual maturity at the age of 3. The adults diet includes shrimp, clams, polychaete worms, and seaweed. They are most abundant from the Gulf of St. Lawrence to Chesapeake Bay.Yellowtail flounders(Limanda ferruginea): Yellowtail flounders are found in the Northwest Atlantic from Labrador south to Chesapeake Bay. Yellowtails have the ability to change to match the colour of the bottom of the ocean in order to blend in with their environment. They can grow up to 47 cm long and weigh about 2.2 lbs and reach sexual maturity at 2 years. Their lifespan is around 10 years. They feed on small crustaceans and marine worms.
Witch Flounders(Glyptocephalus cynoglossus): Also known as "greysole", witch flounders live in deep cold waters in Labrador to North Carolina. These flounders are slow-growing, late-maturing, and long-lived (up to 30 years). They grow to about 72 cm and reach sexual maturity at 4 for males and 6-7 for females. Because of their small mouths, their diet is restricted to very small crustaceans and worms. They are very plentiful throughout areas in Newfoundland such as Bonavista Bay and the Funk Islands. Witch flounders have been commerically fished in Newfoundland since the early 1940's.