Balaenoptera musculus
Blue whales are the largest animals ever known to have lived on Earth. They’re endangered, with only 1,300 to 2,000 remaining in the world.

Blue Whale in the Pacific Ocean
Blue Whale in the Pacific Ocean.

Estimated population: 10,000, endangered.

Ways to identify this species: baleen whale, grayish blue skin with white spots, small dorsal fin set farther back.

Blue Whale Biology

Threats to Blue Whales