Slick

I came across an interesting piece of trivia on the New Scientist web site.

According to this article, mako sharks, which can move very quickly, can raise welts on their skin, creating a rough sandpaper-like finish. When the shark is moving, these welts cause small vortices to be created in the spaces between the welts; the vortices, in turn, create a small 'buffer layer' of water between the shark and the great body of water, reducing the amount of turbulence between the moving shark and the mass of water. Since wake turbulence has a lower pressure than the rest of the water, it tends to slow the moving shark down; reducing the turbulence removes that drag, so that the shark can move faster.

Who knew sharks were so smart?