Friday, December 24, 2010

UPDATE

just letting you guys know i'll be away for a couple of day, (you know, as it is christmastide and all haha)

Thursday, December 23, 2010

How does a shark breathe?


As with other fishes, sharks breathe by extracting oxygen when seawater passes through their gills.

Shark gills are just behind a sharks head and they are not specially covered, like in most fish.

Water pass thorough their gills while sharks are swimming making impossible for most of them to stay still as otherwise they would drown. This process is called ram ventilation.

Tuesday, December 21, 2010

Shark FAQ 7

How do sharks know when something is food or not?


Studies have proved that shark senses are fully responsible for shark hunting.

They commonly use the electrosense for location, even at long distances.

The lateral line sense detects water vibrations usual to most living things.(see left)

The smell and hearing are also used for confirmation, leaving the sight sense the last check when a prey is going to be hunt.

After all these sensorial scanning, sharks sometime even test their food if it is not familiar for them.

Monday, December 20, 2010

Shark FAQ 6

How do sharks find their food?


Sharks are provided with several extraordinary senses that help them find their prey.

This developed and accurate senses has made them very successful for 400 million years.

Usually they use their electrosense system to find prey from long distances.

Then when they are close, smell, hearing and visual senses are used for verifying that the prey is fine for food.



Great White Sharks can smell blood from 1kilometre off, now that's scary!

Sunday, December 19, 2010

Shark FAQ 5

How do sharks communicate?


There is not solid evidence on how sharks communicate, however there is a great belief that the extraordinary senses developed by sharks are involved in any communication between sharks, if any.

Friday, December 17, 2010

Shark FAQ 4

Now, this post is not for the youngin's so if you don't want to know how sharks mate, don't read this!

How do sharks breed?

While some species breed differently.

Mating in sharks has been rarely observed (so no picture for all you perverts), but most species do it while they swim parallel to each other and the male inserts a clasper into female's oviduct.

There are three ways in which shark pups are born:

Oviparity.
Sharks lay eggs.

Viviparity
Sharks have placental links with developing pups. Pups born fully functional.

Ovoviviparity
Method used by most shark species.
Eggs develop inside the oviduct and hatch inside the oviduct where it finishes its development. Pups born fully functional.

Thursday, December 16, 2010

Shark FAQ 3

How big is the Shark Brain?

While brain size cannot be generalized to every shark species, some of them have a Y shaped brain with two bulbs, measuring about 2 feet (60 centimeters)

Some writers have said that the shark brain is the size of a golf ball, but this is not accurate.

The brain mass to body mass ratio in sharks is much lower than humans, but a very good ratio even compared with some mammals.

In general, sharks have complex brains.