Daily News Blog

There is a lot more to sharks that the movie where the Great White is cruising beaches looking for unsuspecting humans to attack. These are marvelous fish that make up over four hundred species and are found throughout the world. Some of these fish eat other fish and krill. Other fish are opportunistic and eat whatever comes in across their path.

For over four hundred million years the year has been inhabited by these fish. They have survived through all the changes that have taken place on the planet. As they have evolved, there has been significant changes made in their physiology that makes them a stunning study in evolution and motion.

The entire body of a shark is designed for forward motion. Many of the species never sleep, but must continually move in order to get the oxygen that they need to survive. In addition, their dorsal fin prevents backward movement. The tail fin on each fish is specifically designed for it’s primary purpose. The Thrasher shark uses it’s tail fin to corral other fish, the Tiger gets maximum power for cruising slowly and for sudden bursts of speed.

A person may be looking at a seven inch shark or a thirty-nine foot shark and will notice the same element of symmetry and controlled movement. Even their skin, dermal dentricle, adds to the fluidity and speed with which they can move. The hide of many types of shark are used for purses, sandpaper, and other commercial industries because of its durability and toughness. The dermal dentricle acts as an outer skeleton and is not related to scales found on other types of fish.

With a body made completely from cartilage and connective tissue and no rib cage the shark is able to move effortlessly through the water. They turn, bend, and twist in a seeming dance of motion and control. Each part of their body performs a vital function to maintain its ability to live for up to 50 years.

There are only a few sharks that jump from the water. The Great White and Mako, are both considered dangerous to humans but do not “hunt” humans. When at sea they often jump from the water to catch birds flying close to the surface. There are several types of shark on the endangered species list because they are hunted for meat, skin, and sport without regard to their survival.

Andries Joubert has been studying sharks for nearly fifty years and is fascinated by shark migration.