Printable activity (student handout) for PROGRAMGills: Allow a fish to breathe. Some fishes have gills covered by flaps. When a fish opens its mouth, the flap closes, drawing water into the mouth ...

Dorsal, anal, and caudal fins are single. Mouths: Enable a fish to eat. Some mouths extend directly from the head of the fish; in others the lower jaw extends beyond the upper jaw.