Blue whales are enormous. In the entire history of our planet there has never lived an animal, that could rival it. It is larger even than the mighty dinosaurs. A fully grown male, during the summer when they feed extensively in preparation for the cold months ahead, can reach up to 30 meters in length and a weight of 200 tons. This is more than twice the size of the largest land-based animal – the Argentinosaurus, which weighed around 80 metric tons. The biggest marine animal, apart from whales, was the Megalodon – a gigantic shark, which was around 50 to 60 tons, but even it could not compete with the blue whale. Everything about it is huge. Their tongue weighs as much as a full-grown elephant and their heart is as big as a car. It beats at around 5 beats-per-minute and can be heard as far as 3 km away. Each beat pumps 500 liters of blood into their system.
Incredibly they reach this size by feeding upon one of the smallest creatures – a shrimp-like type of plankton, called krill. They have a special plate-like attachment to their upper jaw, called a baleen, used to trap these microscopic creatures. It is fringed like bristles and when the whale feeds it opens its jaws wide and fills its mouth, throat and belly. Like this it can consume its own bodyweight in water, which is then pushed out using its tongue. The krill remain filtered and are then eaten. Each mouthful can contain around 500kg of plankton and each day a whale eats close to 40 million krill, or 3,600 kg.
Amazingly, whales, as well as dolphins and porpoises are actually even-hoofed mammals and their closest land relative is the hippo. Blue whales live in all of the planets oceans and spend their summers in the arctic but travel to the equator during the winter. Nevertheless, the populations in the North and the South Hemisphere never meet, because the offset of the seasons.
Not only are blue whales the largest, but they are also the loudest animals alive. Although humans cannot hear them, they can emit sounds as loud as 180 decibels and can travel as far as 1600km. Sadly this is not always enough. There is one individual whale, of unknown species, who speaks at a much higher frequency – 52 Hz – than blue or fin whales. He was first noted in 1989 and has been detected regularly ever since and appears to be the only individual, emitting at such a high frequency, making it the loneliest whale in the world.