Blue whale is a marine mammal which belongs to the baleen whale suborder mysticeti. It is the largest animal known to have existed. The blue whale has a long and slender body, the colour varies from grayish-blue dorsally and somewhat lighter underneath. The dorsal fin can be used for identification.
They are 30 metres (98ft) from rostrum tip to tail notch. The female blue whales are larger than males. A blue whale maximum age is 73years but a blue whale age is measured using ear plugs. They secrete earwax (cerumen) throughout their lives.
They inhabit Eastern North Pacific, Central and Western North Pacific, North Atlantic, Madagascar, Eastern Australia, Northern Indian and Eastern Australia / New Zealand. They feed on a pelagic red crabs. Before a male blue whale can mate with a female blue whale, it has been determined blue whales reach sexual maturity at about 10 years of age and at an average length of 2.5 metres for female Antarctic blue whale.
Blue whale is a favourite food of killer whale. The killer whale is the only natural threat to blue whale. A blue whale weigh up to 400,000 pounds approximately 33 elephant..