The largest mammal on Earth is the blue whale (Balaenoptera musculus), reaching up to 30 meters (98 feet) in length and weighing up to 200 tons. Found in all oceans, it feeds on tiny krill, consuming¹ 4-6 tons daily. Its heart alone weighs 600 kg (1,300 lbs), and its calls are among the loudest of any animal. Once heavily hunted, blue whales are now endangered, with conservation efforts in place to protect them.

地球上最大的哺乳动物是蓝鲸（学名：Balaenoptera musculus），体长可达30米（98英尺），体重逾200吨。蓝鲸分布于全球海域，以磷虾为食，日食量4-6吨。其心脏重达600公斤（1300磅），叫声是动物界最响亮的之一。因过度捕猎，蓝鲸现为濒危物种，正受全球保护措施庇护。