Fish shapes have also uniquely evolved to suit the needs of their aquatic life. The body shapes of fish fall into general categories: Some fish are narrow, with bodies that are taller than they are thin, like sunfish, largemouth bass, or angelfish. Some are flat, with bodies that are shorter than they are wide, like flounder. Some are torpedo-shaped, like tuna or mackerel. Some are tubular and snakelike, such as eels.
Shapes tend to be related to a fish’s habits and habitats. Narrow-bodied fish are extremely maneuverable and tend to live in reefs or densely weeded ponds where the ability to maneuver between rocks or plants is essential.
Flatfish tend to live on the bottom, where their low profiles prevent recognition. Torpedo-shaped fish are built for speed and are found either in open water or in strong currents where less-streamlined fish would be swept away. Tubular fish often live in small crevices and areas that are inaccessible to other animals, rather than in wide-open ocean waters.