Blue Whale

The blue whale is the largest animal that ever lived on Earth. It is also the loudest animal on Earth. These enormous mammals eat tiny organisms, like plankton and krill, which they sieve through baleen. They live in pods (small groups). These gray-blue whales have 2 blowholes and a 2-14 inch (5-30 cm) thick layer of blubber. 

Blue whales are rorqual whales, whales that have pleated throat grooves that allow their throat to expand during the huge intake of water during filter feeding. Blue whales have 50-70 throat grooves that run from the throat to mid-body.

Blue whales grow to be about 80 feet (25 m) long on average, weighing about 120 tons (109 tonnes). The largest specimen found was a female 94 feet (29 m) long weighing more 174 tons (158 tonnes). The females are larger than males, as with all baleen whales. The largest of the blue whales (150 tons) has a heart that weighs about 1,000 pounds (450 kg) and has 14,000 pounds (6,400 kg) of blood circulating in its body. The heart is about the size of a Volkswagon bug car. A human could crawl through the aorta (a major blood vessel).

Blue whales are the loudest animals on Earth! Their call reaches levels up to 188 decibels. This low-frequency whistle can be heard for hundreds of miles. The blue whale is louder than a jet, which reaches only 140 decibels! Human shouting is 70 decibels; sounds over 120 decibels are painful to human ears. 

It is estimated that there are about 10,000-14,000 blue whales world-wide. Blue whales are an endangered species. These whales (and many other large whales) were over-hunted for many years, since their meat, oil, and other body parts are very valuable. Since whale hunting has decreased in the last few decades, their populations are starting to recover. 

(Pic from: misterjogja.com)

(From: www.enchantedlearning.com)

(from: www.bayschools.com)