Solefish spend their adult life lying with one side flat on the seabed, while the other side faces up and is camouflaged, so the fish can lie motionless for hours, waiting for a tasty morsel to swim by. When this happens, the solefish lunges upwards and suddenly opens its mouth to vacuum the hapless fish inside. Since solefish spend all their adult lives with one side up and the other side facing the seafloor, they have evolved several morphological adaptations, such as having both eyes located on one side of their head, giving them a sighted (up) side and a blind (down) side.
They are born with one eye on each side of their head, but undergo larval metamorphosis where one eye migrates to the other side of the fish’s head late in larval development, producing asymmetrical juvenile fishes. By the time the skull is fully ossified, the eyes are permanently fixed in place.