Blue Whales

By J Fernandez

The blue whale is the largest animal on the planet (as large as an airplane), weighing as much as 200 tons (approximately 33 elephants). The blue whale is a marine mammal and a baleen whale. Reaching a maximum confirmed length of 29.9 meters and weighing up to 199 tonnes, it is the largest animal known ever to have existed. The blue whale's long and slender body can be of various shades of grayish-blue dorsally and somewhat lighter underneath.

Four subspecies are recognized: B. m. musculus in the North Atlantic and North Pacific, B. m. intermedia in the Southern Ocean, B. m. brevicauda in the Indian Ocean and South Pacific Ocean, B. m. indica in the Northern Indian Ocean. There is also a population in the waters off Chile that may constitute a fifth subspecies.

In general, blue whale populations migrate between their summer feeding areas near the poles and their winter breeding grounds near the tropics. There is also evidence of year-round residencies, and partial or age/ sex-based migration. Blue whales are filter feeders; their diet consists almost exclusively of krill. Blue whales are found in all oceans except the Arctic.

They generally migrate seasonally between summer feeding grounds and winter breeding grounds, but some evidence suggests that individuals in certain areas might not migrate at all. Information about distribution and movement varies with location, and migratory routes are not well known. In general, distribution is driven largely by food availability— they occur in waters where krill are concentrated.

Blue whales sometimes swim in small groups but are more Often found alone or in pairs. They generally spend summers feeding in polar waters and undertake lengthy migrations towards the equatorial waters as winter arrives.

The blue whale has a heart 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.

Blue whales are found in all oceans except the Arctic. They generally migrate seasonally between summer feeding grounds and winter breeding grounds, but some evidence suggests that individuals in certain areas might not migrate at all. Information about distribution and movement varies with location, and migratory routes are not well known. In general, distribution is driven largely by food availability—they occur in waters where krill are concentrated.

They are the loudest animals on Earth and are even louder than a jet engine. Their calls reach 188 decibels, while a jet reaches 140 decibels. Their low frequency whistle can be heard for hundreds of miles and is probably used to attract other blue whales.

Whales are marine mammals and like all mammals they require air to breathe and must come to the surface of the waterto take in oxygen. Unlike fish these marine mammals are not equipped withgills,which fish and other aquatic animals use to extract oxygen from water; Instead whales need to rise to the surface of the water to inhale and exhale oxygenthrough their blowholes.

In order to make it easier to breath the whalesblowhole(s) are located at the top of the whales head and act as a passageway to the trachea where air passes through the air passage and fillsthe lungs. Having their blowhole on the top of their head makes it easier for them to breathe with minimal effort, especially during times of rest when they can be seen logging around near or at the surface of the water. While whales are known to breathe through their blowholes they are unable to breathe through their mouth because the trachea is not connected to the whales throat.