Balaenoptera physalus, commonly known as the fin whale, is the second-largest animal on Earth, reaching lengths of up to 85 feet (26 meters) and weighing as much as 80 tons. This species is known for its slender body and distinctive dorsal fin, which can be seen when it surfaces for air. Fin whales are found in oceans worldwide, often in deep waters. These whales primarily feed on small fish and krill, using a method called lunge feeding to take in large amounts of water and prey. They are known for their speed, capable of swimming up to 23 miles per hour (37 km/h). Conservation efforts are ongoing to protect Balaenoptera physalus from threats like ship strikes and entanglement in fishing gear.