Blue whale

The largest animal that has ever lived

The blue whale is the biggest animal that has ever lived on Earth — bigger than any dinosaur! It's 30 metres long — as long as 3 buses. Its heart is the size of a small car, and its tongue weighs as much as an elephant. Yet it eats the tiniest creatures — krill, 4 tonnes a day! A blue whale's voice is the loudest in the world — it can be heard 1,000 km away.

The blue whale (Balaenoptera musculus) is the largest animal ever, up to 30 m (record 33 m) and 150–200 tonnes. It has no teeth — it filters water through baleen plates and eats up to 4 tonnes of krill a day, taking in 80 tonnes of water in a single gulp. Its call is 188 decibels — louder than a jet engine — low-frequency and travels hundreds of km through the ocean. Its heart weighs 180 kg and beats 2–10 times a minute. In the 20th century whalers killed more than 360,000 blue whales, leaving fewer than 1,000; protected since 1966, there are now 10,000–25,000. Found in all oceans, feeding in polar waters in summer and migrating towards the equator in winter.

Fun facts

• A blue whale's heart is the size of a car — a child could swim through its blood vessels!
• A blue whale calf is born 7 m long and gains 90 kg a day — 4 kg every hour!
• A blue whale's call is 188 decibels — louder than a jet engine.
• A blue whale is so big that 50 people could stand on its tongue.