Dorsal Fin
Imagine trying to keep your balance while walking on a windy day. Just like you instinctively adjust your body to stay upright against the gusts, a dorsal fin helps marine and freshwater vertebrates maintain stability as they move through water. The dorsal fin acts like a natural stabilizer, akin to how you use your arms or adjust your stance to prevent being knocked over by the wind, ensuring the animal can swim in a straight line without being easily toppled by currents.
Practice Version
Dorsal Fin: A fin located on the back of most marine and freshwater vertebrates. Dorsal fin. It helps fish and other aquatic animals to stay stable and steer while swimming.