It’s the biggest animal ever known to have existed with it’s 33 metres (108 ft) in length and 190 short tons (170 metric tons) or more in weight. Long and thin, it’s body can have different grey-blue on it’s back and a bit clearer under it. It has 3 subspecies, the B.m musculus in the North Pacific and Atlantic, the B.m intermedia in the Antartica Ocean and the B.m brevicauda in the Indian Ocean and the South Pacific. The B.m indica discovered in the Indian Ocean also could be an other subspecie.

Like other whales, the Blue Whale eats some krill, small crustacean but also some little fish and sometimes some squids. There was a lot of Blue Whale before the 20th century but during forty years, they were hunted by whalers then protected by the international community in 1966. A report in 2002 considered that there was between 5 000 and 12 000 whales overalls in the world. Before the industrial hunting of the whale, the biggest population was in the Atlantic Ocean with approximatively 240 000 (from 202 000 and 311 000). It’s now considered as an endangered specie.