The document discusses four marine animals: seahorses, jellyfish, sea turtles, and dolphins. Seahorses live in warm, calm tropical waters around the world. Jellyfish have existed in oceans for 500 million years and can be found from the surface to ocean depths, with some living in fresh water. Sea turtles have lived for 180 million years, mostly in the southern oceans, and can live over 150 years. Dolphins are aquatic mammals that can jump up to 7 meters high out of the water and are carnivores.