Flounder are flatfish that eat shrimp, crustaceans and other fish. Adult flounder can eat between 4 and 8 percent of their body weight every day.
Flounder have adapted a body shape and camouflage-ready color scheme that allow them to lie in wait on the ocean floor well concealed from potential prey. When prey moves within close range of the flounder's mouth, it strikes quickly. It's this ambush style of predation that characterizes flounder hunting techniques. They use this style of hunting throughout most their lives, but they focus on prey that's suitable for their size at a given age.
As hatchlings, flounder eat small prey such as plankton, and as juveniles they graduate to hunting small fish, crustaceans and worms. Adult flounder will eat shrimp and schooling fish such as anchovies, mullet and pigfish.
In addition to having developed suitable coloring to help them blend in on the ocean floor, flounder can shimmy their way down into the sound and bury their thin, flat bodies with a layer of sand or rock. This blanket of ocean floor sediment is a very effective camouflage technique, and it helps make flounder successful predators. Of course, flounder themselves are often caught and eaten by humans, but it is not a protected species.