Many aspects of the sharks biology and ethology are not very well known, above all because of the difficulty to study these fishes in their natural environment and for their bashful and solitary behavior.. Here you will find some questions about sharks life without answer..

It seem that the pressure practiced by the bite of a shark Carcharhinus obscurus of around two meters is three tons for square centimeter! To that value could arrive then that of a white shark of the length of seven meters?!

According to Walter Starck the strips coloration white and black horizontal, that reproduces that poisonous snakes of sea can be used as anti-shark protection in the cases in which it is had to be to narrow contact with these animals (es: taken back video, search, etc.).
The author remembers, to confirmation of this, the coloration of the pilots fish that often accompanies the sharks in their swimming and the declarations of the king of the island Tonga that makes to paint his people to white and black strips before plunging themselves in sea to fish. Can these explanations have therefore a real value??

The hammer shark Sphyrna lewini, but also other species (Sphyrna zygaena, Sphyrna tudes, Sphyrna tiburo) usually solitary, has been observed to swim in numerous flocks. This situation appens in the Red Sea, Costa Rica, Colombia, but also Hawaii, South Africa and in the Mediterranean waters. These sharks don't have to unite themselves in flocks to avoid the raiders, and probably they don't even do it for reproductive motives.. Which is therefore the explanation??