A lone shadow moves through the azure waters. A spout of water and air shoots into the sky thirty feet high from the blowhole in its head, sparkling in thesetting sun. Over eighty feet long, this fascinating animal is the biggest organism ever known to have lived on Earth. This magnificent creature is called a blue whale. As well as the largest, bluewhales are one of the most intelligent species in the ocean.
This species of whale can grow up to a hundred feet long and weigh up to one hundred and eighty tons. Their bodies are shaped into a long,slender oval, with long flippers and a short, stubby dorsal fin on top. On the top, they are a soft blue-gray color, speckled with white, while on the bottom they are a lighter gray, with spots ofbrown or dark gray. Their large, powerful tails are their distinctive figure, because each whale has its own special markings on the underside, patterns of spots, stripes, or markings. The head of a bluewhale is shaped in a smooth curve, with a ridge running from the blowhole to the upper lip. The mouth, filled with plates of baleen, can hold up to ninety tons of krill and seawater when it is fullyexpanded.
Blue whales travel at speeds of around twenty-five mph (fifty kilometers per hour), but slow down while feeding. During feeding, they will lunge at a group of krill that are one hundredmeters below the surface and then squeeze out the seawater, leaving the krill caught against the baleen plates. An adult blue whale will eat around 3,500 kilograms of krill every day to meet its dailycalorie requirement of one and a half million.
Blue whales normally live alone or with one other individual, not in pods as many other whales do. However, during the mating season, blue whales havebeen seen densely populating small areas. Scientists estimate that the lifespan of this amazing species is around eighty years, but they have no concrete evidence. The longest recorded study of one...