须鲸, also known as the baleen whale, is a large marine mammal found in oceans worldwide. It is characterized by its long, flat baleen plates, which it uses to filter food from the water. These whales primarily feed on small fish and krill, swimming with their mouths open to take in large amounts of water and then pushing it out through the baleen. These whales can grow to impressive lengths, with some species reaching up to 100 feet. Humpback whales and blue whales are among the most well-known types of须鲸. They are known for their acrobatic behaviors and haunting songs, which can travel long distances underwater.