Sharks

Sharks had always been in the fear list of many people especially me. Movies such as Jaws had been a big influence in the public and had installed fear within the people.

So what about sharks and are they really ferocious?

Sharks are a type of fish that belong to a class known as chondrichthyes. Chondrichthyes or cartilaginous fishes are jawed fish and their skeletons are made of cartilage rather than bones. Sharks are also in the same class as rays and skates.

Do all sharks eat meat?

The answer is no. Most of the sharks eat meat, especially the ones that have sharp teeth. However there are some sharks that do not eat meat. Sharks such as the whale shark and the basking shark do not eat meat, they eat small, tiny, microogranisms named plankton.

Sharks have sharp vision.

Sharks are actually a fish with super senses. The sharks' eyes has a mirror like layer that allows it to see better. With many species of the sharks, two thirds of the sharks' brain is dedicated to smell.

Sharks have a few unusual senses. One of it is the lateral line. The lateral line are lines of canals that that go from the shark's head extending to its tail, and is used to detect vibrations of the water surrounding them. Another sense is the ampullae of Lorenzini, basically a sensory organ that the shark uses to detect the electric feel coming of of their prey. All of the senses alerts the sharks of their potential prey.

Do sharks prefer to prey on human?

There are some suggestions saying that sharks do not actually prefer humans. But humans seemed like easy prey as we don't swim as fast as the other fishes. Mostly the sharks will bite anything that come in their way.

Some expert suggests that sharks actually do not like human flesh because human blood are made up of iron, rather than fish blood that contains more copper ions. But more studies need to be done. But one thing that is important, if you encounter a shark that is about to attack you, j ust get out of the water as fast as possible. That is the most logical thing to do.

How do Sharks reproduce?

Most of the fish under the sea lay eggs, but sharks, they do lay eggs, but the eggs are fertilized inside the body of the female shark. The male sharks has an extension of the pelvic fins called claspers, that is used to transfer the sperm to the female to fertilize her eggs.

There are some sharks that lay their eggs. But, most of the sharks give birth to live young, the embryo of the sharks develops inside the female body during the gestation period. The gestation period for the sharks ranges from several months to two years.

Baby sharks are called pups. Pups are born complete with a set of full teeth and are ready to take care of themselves. After the pups are born, they usually swin away from their mother, as the mother would prey on them.

There are 3 ways that sharks are born :

1. Oviparity

These sharks lay eggs, which are protected by an egg case, sometimes called 'mermaid purses'. The sharks deposits the egg cases in the sea and the shark embryo is nourished by the yolk in the egg sac and chews itself out when it is fully developed.

2. Viviparity

Viviparous sharks carry their embryos throughout the whole gestation period. They give birth to live shark pups similar to how mammals give birth. The eggs hatch inside the female's body and the babies are fed by a placenta which transfers nourishment from the mother to the babies.

3. Ovoviviparous

The babies hatch inside the female body but there is no placenta to nourish the babies. The pups will eat any unfertilized eggs and also they eat each other. Very few babies survived due to this form of sibling cannibalism.

Threat To sharks

I guess this is an issue that is becoming well known. The shark fin's soup. For ages, humans had been capturing sharks and then cutting off their fin before tossing the poor shark back to the sea. And sharks without their fins, they can't swim and when they can't swim, they can't search for food, and in the end they die. When shark finning happens, the shark is basically left to die a long and miserable death. This should stop!!! And because of this, the sharks population are declining in the past few decades.

There are a few things, normal people like us can do. First and foremost, stop eating shark fin's soup. Just remember when the demands stop, the killing will too. After all, like Gordon Ramsay said, the soup tasted nice not because of the shark fin, and in fact can be substituted by other meat, such as duck or crab meat.

You guys can see Ramsay's video on shark fins and also shark finning here.

For more info in shark conservation, you can visit Shark Research Institute.