Their skeletons are made of cartilage rather than hard bones. The cartilage does not support the internal organs as well as bones do. Death can occur if a shark is out of water for more than a few minutes. Thus, the life cycle varies greatly.

Scientists classify the shark as an unintelligent animal. In spite of this, they survived without changing much for over 300 million years. Each sharks life span differs. The lemon shark lives a quarter of a century, some species live up to a century.

One of those with longevity is the Piked Dogfish with a life span of 70 to 100 years. Different species also have different birthing processes. There are three ways. One is to lay eggs and swim away, another is to produce eggs but carry them till hatching time. The third way is carrying them internally as humans do. The shark fetus is nourished by an umbilical cord as with mammals.

Gestation periods vary from 9 months to 22 months. The mother gives birth to one, or up to an astonishing 100 pups at a time. One feature that humans might envy is that they grow additional teeth throughout the life span. As the old teeth wear out, new ones continue to replace them for however many years the shark lives.

Young sharks are called pups. The lemon shark, because it is territorial, has been studied more thoroughly than any of the others. A shark is born and reaches sexual maturity in about fifteen years.

For the first three years of life, the lemon shark pup stays within a territory the size of 11 football fields in the warm, murky waters near Bimini. As they grow, their habitat expands with each year of life. They hunt for food in increasingly larger areas.

By the age of sexual maturity, which is 14 to 16 years for the female and 13 for the male, they live and hunt in an approximately 36 mile territory. By this age they are about seven feet long. The lemon shark lives approximately 25 years. During her life she is able to produce approximately five litters under optimal circumstances. The male sharks life cycle is about the same length.

In his studies of sharks one feature that has always intrigued Richard Williams is the sharks life cycle.

The Baleen whale on the other hand filters its food in the water by means of a comb like structure. The Baleen is by far bigger than the toothed whale is and this whale has two blow holes which are situated on the top of its head. The very largest mammal is the Blue whale although it lives in the ocean is considered to be the largest mammal on earth sometime exceeding 29 meters in length. Due to the creature size it has to eat 4 tons of krill a day and this species is threatened by man.

From the biggest to the smallest which is the dwarf sperm whale and measures around two and half meters in length. These creatures are mammals and do not fall under the fish category they also spend their whole life in the water. Not only are these mammals large but they are also exceptionally intelligent.

A Whale just like all mammals breathe air into their lungs through the blow holes and also have fine hair that covers their body. They have a chambered heart and they are warm blooded, they also have the capability to maintain a high body temperature. Like all mammals they have mammary glands from which they feed their young.

The killer whale as well as the short fin pilot whale swim withgreat speeds and can reach around forty eight kilometres ph. These majesic creatures display a lot of activity in the ocean some jump extremely high out of the water and they are also known to surface their heads in order to have a look around.

The whale’s worst enemy is humans and due to humans many of the whale species are now critically endangered and not too far in the future will these mammals become extinct through being hunted.

In her studies of whales one feature that has always fascinated Anne Stark is whale communication.

As far as all of the varied whale species go, there doesn’t really seem to be one that doesn’t migrate. In fact, most end up on very long trips in order to travel from one area in a part of the world to another area in a different part of the world. Most patterns seem to show a migration from higher or lower latitudes to lower or higher latitudes elsewhere.

Normally, a typical whale will spend one part of the year feeding vigorously and then begin to migrate to a part of their particular ocean in order to begin the process of mating and then giving birth to a calf. These trips from feeding grounds to mating and birthing grounds can encompass thousands of miles of travel. This is an ancient act bred deeply into each species.

A typical example of such migratory activity is the blue whale. Almost every blue whale undertakes a migration, spending the summer in cooler waters in the Northern Hemisphere and building up fat stores from extensive feeding. Come winter, though, it begins a move to the South and the warmer waters that exist there. Why, though, does a blue whale moved in this particular pattern?

Most marine biologists have a couple of different answers, with the most common being that the whale has learned to evolve in order to take advantage of feeding opportunities existing in cooler waters but also to take advantage of birthing and mating environments in summer waters. These waters also give a calf born of a mother to learn how to begin to take care of itself in a more welcoming environment

What is for certain about these magnificent animals is that their lives are impressively complex and quite wonderful to behold. They can undertake migrations thousands of miles in length in order to carry out their full lives. Their behavior patterns are involved and ancient in ways we cannot understand, and these extremely intelligent mammals continue to beguile us immensely.

whale migration has long intrigued Allan Hoffland while watching whales along the East Coast of Southern Africa.

Female whales must choose wisely when mating. They want a bull that is healthy and strong so their calf will be healthy and strong. There is a fair amount of competition between the males and the whales mating rituals can be challenging.

During the whales mating rituals, the competition is adequate. The bulls will sing and sometimes fight in the effort to attract a mate. As it is, mating happens only once every two years. The bulls though, will spend time looking for the females. For the large whale variety, traveling to the tropics to mate and give birth, is often seen.

Using their vocal capabilities, males sing love songs in attempts to win over a female. While what we here my sound like clicks and squeaks, to the whales it is a song. Often rhyming, with verses and changing the songs to try to outperform one another. These songs can last for 10-20 minutes and are often repeated for hours. There are other tactics used to gain attention as well.

Some whales, like the Narwhal have a tusk that protrudes from their lip. The males have been known to use these tusks in battle to win a female. When these whales battle any female or calf nearby move out of the way to avoid injury.

Winning the approval of a female results in a courtship period. Touching each other, posing, singing and swimming in certain patterns is all part of dating. Getting to know one another is important before the mating begins. After they feel they know each other well enough, the belly to belly mating starts.

After the mating ritual has ended, some whales leave and some stay. Those that leave return to the group of males they travel with. Those that stay protect the female and calf and form a family unit.

In his studies of whales one feature that has always fascinated Jan van Nickerk is the whales mating rituals.

The demand for whale blubber has surged on despite the fact that it is not so necessary to use it as a base material for modern day products. Disregard for the whale by fishermen and organizations alike in international waters does not help the situation, indeed it exasperates it. The ongoing slaughter of the whale for its meat and by-products, such as oil, perpetuates this situation. Despite this, there are some who still need to hunt the whale.

The blubber of a Bowhead whale, traditionally hunted by the Eskimos of Alaska, accounts for up to 20% of its total body weight. This jelly-like material which helps protect the animal in freezing waters has a wide range of uses for them.

The small number of Eskimo communities that survive to this day (nine in total) live off the Bowhead whale, taking great care to use all parts to the maximum benefit of the people. Uses from the whale blubber can include oils for candles, and fuel for lighting and heating, to name but a few. Of course there is a great need for the meat too. This need for such basics is not so transparent in other parts of the world where alternative products and fuel sources are readily available.

The Eskimo may also be an endangered species in the near future. Are we not obliged to support and better understand the needs and culture of a people who are also fighting for their continued existence? A total ban on the tradition of whale hunting would possibly quicken the deterioration of these relatively small communities already threatened by global warming. Not only does hunting provide whale blubber, food, and oils, but it also continues the direct relationship between the Bowhead and the cultural identity of the people.

The good news is that the growing Bowhead numbers will be looked upon in favour with a likely continued pardon for these unique hunters. Coupled with the greatly enhanced strategies and methods for harvesting their prey, the future of the Eskimo looks far better than it did not so long ago.

What must be tackled comprehensively is the ongoing slaughter of whales in international waters by a small group of whalers intent on selling whale blubber to a diminishing number of customers back home. A collaborative approach by the international community will surely help to secure the future of the whale. There are so many other options out there to choose from.

Many people believe that dinosaurs were the largest animals to have ever lived on this planet, and they may be correct in terms of land animals. However the Blue Whale is actually the largest animal found on earth and although it lives in water, it breathes air.

It is also the loudest animal of any other found on Earth, its call is actually louder than a jet engine, it has been measured at 188 decibels. They dive to about 350 feet and are able to stay underwater for around an hour.

These animals are carnivorous, and they eat tons of the tiniest food imaginable. Their diet is made up of plankton, krill, small fish and other tiny organisms. They feed mostly in winter, when they can be found in arctic seas and eat as much as 4100 tons of food a day. Blue whales are rorqual so they use baleen to sieve their food from the thousands of liters of water they suck into throat grooves.

Although the underside of the whale varies in color and is lighter than the rest of the body, they are actually a grey blue. They grow to weigh approximately 120 tons and the females are larger than the male of the species. One female was found to weigh 174 tons! Their tongue weight about 4 – 6 tons and their heart is the size of a VW Beetle and weighs more than 1000 pounds.

Blue whales swim in pairs or small pods and often live individually and are very fast swimmers. If they are in danger they have been known to swim as fast as 24 – 30 miles per hour. They mostly live on the surface of the ocean and are found in virtually every ocean throughout the world.

Their breeding season is mostly during winter, and the calf takes 11 – 12 months to grow inside the mother. The mother whale gives birth in warm, shallow water and the baby comes out live and tail first. It instinctively makes for the surface of the water and is helped by the mother. When a blue whale is born it weighs between 6 and 8 tons and is about 25 feet long. They mature at about 15 years old and have only two known predators, killer whales and man!