More information: http://www.sharks-world.com/shark_anatomy/

There are more than 400 shark species in the ocean, but they have the same basic anatomy... all of them have cartilage skeleton.

More information: http://www.sharks-world.com/

Electroreception is the ability to detect electric fields that all living beings generate when they move.

More information: http://www.bioexpedition.com/dolphin-echolocation/

One of the amazing things that dolphins use for communication and to find out about their environment is echolocation.

More information: http://www.dolphins-world.com/dolphin-intelligence/

Dolphins are very intelligent and their brain structure shows why.

More information: http://www.dolphins-world.com/

Birth, lactation and growth of baby dolphins. Interesting facts about baby dolphins.

More information: http://www.bioexpedition.com/penguin/

and http://www.penguins-world.com/types-of-penguins/

- Emperor and king penguins are very similar to the naked eye, but they have both physical and geographical differences.

More information: http://www.penguins-world.com/

Penguins are birds, but they don't have the ability to fly. Which is the reason?

More information: http://www.penguins-world.com/emperor-penguin/

"I do not think anybody on Earth has it worse than an Emperor penguin.” Who said that and why?

Information about grey wolf: http://www.wolfworlds.com/gray-wolf/

Scientific evidence shows that domestic dogs are descended from the gray wolf!

More information: http://www.wolfworlds.com/wolf-communication/

The howl of the wolf can be heard from miles around. It is the trademark by which these animals are known, but, why do they do it?