Blue whale

     

Description:

The blue whale is the largest animal ever known to have existed. During the 20th century, the species was an important whaling target and even after it was protected and commercial whaling stopped in 1964, exploitation efforts by the former Soviet Union persisted.

It is difficult to imagine the size of the blue whale, the largest animal inhabiting the earth. There are records of individuals over 100 feet (30.5 m) long, but 70-90 feet (23-27 m) is probably average. A good way to visualize their length is to remember that they are about as long as three school buses. An average weight for an adult is 200,000 to 300,000 pounds (100-150 tons). Its heart alone is as large as a small car. Blue whales are an overall blue-gray color, mottled with light gray. Cold water diatoms adhere to their skin and sometimes give their bellies a yellowish tinge, giving the blue whale its nickname of "sulfur bottom." Blue whales are long and streamlined. Their dorsal fins are extremely small, and their pectoral flippers are long and thin.over 800 plates.

Physical Appearence:

The blue whale's heartbeat can be detected from two miles away and its heart is the size of a Volkswagen Beetle. Its stomach can hold one ton of krill and it needs to eat about four tons of krill each day. It is identified by a relatively small dorsal fin, a fairly rounded rostrum (anterior part of the skull), and approximately 90 ventral grooves which reach the navel.

Blue whales have row of 300- 400 baleen plates on each side of the mouth, which are black in color and range in length from 50 cm in front to 100 cm in back.

The species dives for 10 - 20 minutes periods, and usually feed at depths of less than 100 m. Average travel speed is around 22 km/hr, although they may swim as fast as 48 km/hr if they perceive a danger

The largest recorded length for a blue whale is 33.5 m (110 feet), but sizes tend to run more in the range of 80-100 feet. Females are up to 10 m longer than males. At 100 feet, a blue whale would weigh close to 200 tons, or 400,000 pounds.

Seeing and Hearing:

It is hard to know the answer to this question since blue whales are so big and live in the open ocean.   It is thought that baleen whales (including blue whales) probably have excellent hearing, especially at low frequencies, which is valuable in the dark ocean environment where vision is less useful

Range/Habitat:

Blue whales have been found in every ocean of the world. Blue whales swim individually or in small groups. Pairs are very commonly seen. Approximately 2,000 blue whales live off the California Coast and migrate to Mexico and Costa Rica.

Diet:

Blue whales filter their food through their baleen plates. Blue whales eat krill (euphausiids) and copepods.  A blue whale can eat up to 8,000 lbs. of krill during its peak consumption period. It is estimated to take 2,200 lbs. of food to fill a blue whale's stomach