Blue whales are the biggest animals that have ever inhabited our planet. These marine mammals grow up to 22 metres in length and to a weight of 150,000 kilograms. Their tongues alone weigh as much as an elephant in some cases and their hearts can be as big as an automobile.
The most interesting detail about these huge creatures is the fact that they reach these immense body sizes by consuming tiny shrimp-like animals called krills alone. In some seasons, a single adult blue whale eats about 4000 kilograms of krill a day.
Blue whales belong to the family of baleen whales. Baleen is a fringed plate made of fingernail-like material that is attached to their upper jaws. These giant animals feed by first gulping a great amount of water through their mouth and then they expand the pleated skin on their throat and belly to take it in. After this, the whales use their massive tongue and force the water out through the thin, overlapping baleen plates. This process leaves behind a large volume of krill, which gets consumed by the whales. Blue whales are found in all the oceans, except the Arctic. They occasionally swim in small groups but they move about in pairs or stay alone.
They now face a severe threat due to whaling and are considered endangered according to the IUCN Red List.
Picture Credit : Google
