Dorsal fins are the prominent fins located on the back of many aquatic animals, including fish and some marine mammals like dolphins. These fins help stabilize the animal while swimming, preventing it from rolling over and aiding in steering. The shape and size of dorsal fins can vary significantly among species, with some being tall and triangular, while others are shorter and more rounded. In addition to their stabilizing function, dorsal fins can also play a role in communication and display. For example, the dorsal fin of a shark can be a key identifier for species, and its movement can signal aggression or readiness to mate.