One Page. A Shark is made of Sandpaper
A Shark is made of Sandpaper
Sharks are older than the known dinosaurs. Sharks have been around for about 400 million years. Even before dinosaurs walked around, sharks made the seas unsafe.
Sharks are so well adapted to their environment that they have hardly evolved in the last 150 million years. Sharks are cartilaginous fish, just like rays.
That means they have a flexible skeleton, which makes them very flexible. A shark's skin is made up of small hard tooth-like scales. This makes a shark feel like sandpaper.
These teeth not only protect the shark's skin from injury, but also reduce eddies of water moving past the shark's skin as the animal swims. This makes them more streamlined and among the fastest swimmers in the ocean.
So, if you were to pet a shark, it would feel a bit rough.
In the distant past, shark skins were dried and then used as sandpaper for wooden figurines.
This abrasive was then called "shagreen".
Later, pieces of sharkskin were glued to thin wood sticks and sold as nail files.
Endangered Species
Unfortunately, sharks are a delicacy for many. Just think of the shark fin soup.
Shark fin soup is a traditional soup or stewed dish found in Chinese cuisine. The shark fins provide texture, while the taste comes from the other soup ingredients. It is commonly served at special occasions such as weddings and banquets, or as a luxury item.
Some of the sharks are already "endangered species" due to the extensive shark catch. They are included in CITES Appendix II, the Convention on International Trade in Endangered Species, as has been concluded at the CITES conference in Bangkok (2013).
These are the hammerhead shark (Sphyrnidae), the whitetip shark (Carcharhinus longimanus) and the porbeagle shark (Lamna nasus). From now on, the three species can only be fished from the sea on the basis of scientifically determined quotas.
