Flatfish

The order of Pleuronectoidei contains the flatfish and flounders. These fish live in temperate waters and live on the benthic region. As juviniles they are symmetrical, however as they develop one eye migrates to the other side of the head until both eyes are on the same side. As the name suggests, flat fish are laterally compressed. Most of these fish are dextral, with both eyes on their right, however there are some species which are sinistral, with both eyes on the left. Still, some species vary in right/left sidedness and get a mix of both types of fish. Some species have paired fins and some have fused dorsal, anal and caudal fins. As you can see, there is great diversity among the flat fishes.