Blue Whales Essay

Blue Whales

The Blue whale is the largest creature of the sea, in fact, it is the largest creature known to man. Contrary to what most people think, even though Blue whales live in the sea, they are mammals. They breathe air, have their babies born alive and can live anywhere from 30 to 70 years. The Blue whale is a baleen whale, and instead of having teeth, Blue whales have around 300-400 baleen plates in their mouths.

They fall under the category of the rorquals, which are the largest of the baleen family. The scientific name of the Blue whale is,

Balsenoptera musculus.

Introduction

Whales are separated into two groups, the baleen and the toothed whales. The blue whale is the largest baleen whale and the largest animal

Baleen is made of keratin, the same material as our fingernails. They live in pods, the have two blowholes. The blue whale has a 2-14 inch (5-30cm) thick layer of blubber. Blue whales (Balaenoptera musculus) are baleen whales

(Suborder Mysticeti). They are one of 76 species and are marine mammals. Background

The Blue whale is called a ^rorqual^, a Norwegian word for

^furrow^ referring to the pleated grooves running from its chin to its naval. The pleated throat grooves allow the Blue whale^s throat to expand during the huge intake of water during filter feeding; they can

^hold 1,000 tons or more of food and water when fully expanded^ (Small

1971). Blue whales have 50-70 throat grooves.

Blue whales grow up to about 80 feet (25m) long on average, weighing about 120 tons. The females are generally larger than the males, this is the case for all baleen whales. ^The largest specimen found was a female 94 feet (29m) long weighing more than 174 tons^ (Satchell

1998). The head of the Blue whale forms up to a quarter of the total body length. Compared with other rorquals, the head is very broad.

The blue whale heart is the size of a small car and can pump almost

These songs may be used for locating large masses of krill (tiny crustaceans taht they eat) and for communicating with other blue whales.

Blue whales typically are found in the open ocean and live at the surface. They are found in all the oceans of the world. The majority of Blue whales live in the Southern Hemisphere. The subspecies found in the Southern Hemisphere are the balaenoptera musculus. The smaller populations inhabit the North Atlantic and North Pacific. These

Northern Hemisphere Blue whales are the balaenoptera brevicauda. They migrate long distances between low latitude winter mating grounds and high latitude summer feeding grounds. They are often seen in parts of

California, Gulf of California (Sea of Cortez), Gulf of St. Lawrence,

Canada and the northern Indian Ocean. Blue whale breeding occurs mostly in the winter to early spring while near the surface and in warm waters. ^The gestation period is about 11-12 months and the calf is born tail first (this is normal for cetaceans) and near the surface in warm, shallow waters^ (Hasley 1984). The newborn instinctively swims to the surface within 10 seconds for its first breath; it is helped