A blue whale's arteries are as big as drain pipes and its tongue weighs 4 tonnes. It's mouth is so huge that a football team could stand on its tongue!
A newborn calf drinks around 230 litres of its mother's rich milk each day - her milk is about 50% fat, so not surprisingly, the calf gains weight quickly, putting on about 4kg per hour! By the time it is weaned (stops drinking milk) at 7-8 months old, the calf weighs around 23 tonnes.
Blues feed by gulping krill and water, taking in maybe 40-50 tonnes in a single mouthful. The whale then pushes out all the water and traps the krill using its hundreds of furry, comb-like ‘baleen plates’ which hang from its jaw and act like a giant sieve. Their baleen is the longest of all the rorqual whales, but it is particularly wide in relation to its length (90cm to 1m long; 50 to 55cm wide).
Blues must eat around 1.5 million calories each day, equivalent to around 4 million krill.
Blue whales are usually observed to travel either singly or in twos and threes (however, in a creature this immense, the usual rules on 'personal space' may not apply and what we perceive as a solitary migrating blue may in fact be 'travelling in company' with others, maybe several kilometres apart!).
