Okay, so you know how fish have tails to help them swim? Well, some animals that live in the ocean, like whales, dolphins, and sharks, also have tails that are kinda like fish tails, but they look different. We call these tails "sea tails."
The sea tails can be really big, like a whale's tail, or smaller, like a dolphin's tail. They are really important for these animals because they use them to swim and move in the water. The tail moves back and forth, which creates a force that pushes the animal forward, like when you kick your legs to swim in the pool.
Sea tails are different from regular tails because they have a special shape that helps them move efficiently in the water. They are usually long and narrow, with a fin or fluke at the end. This fin or fluke is what helps the animal move forward.
Whales, for example, have big, strong tails that are shaped like a triangle. This helps them generate a lot of power when they move through the water. Dolphins, on the other hand, have smaller tails that are shaped like a crescent moon. This shape allows them to move quickly and change direction easily.
So, sea tails are just special tails that some animals in the ocean have. They use them to swim and move around in the water, and they are really important for these animals to survive in their environment.