Shark Fun Facts by Vivian Vallarsa
Sharks are very interesting creatures. They are a type of elasmobranch fish, which are characterized by their cartilaginous skeleton, five to seven gill slits of the sides of their head, and pectoral fins that are not fused to their heads. Sharks range in size from the dwarf lanternshark, which is only 17 centimeters in length, to the whale shark, which reaches 40 feet in length and are the largest fish in the world.
Sharks do not have bones; the term “elasmobranch” translates to “fish made of cartilaginous tissue.” Their cartilaginous skeletons are much lighter than bone, and their livers are full of low-density oils, both of which help them to be buoyant. Even though they don't have any bones, they are still able to fossilize. As sharks age, they deposit calcium salts into their skeletal cartilage to help strengthen it. This causes the cartilage to fossilize just like bones do.
There are over 500 species of sharks roaming the waters. They come in all different shapes and sizes from hammerhead sharks, which have flattened and laterally extended heads, to the frilled shark, which although now extinct, had a serpent-like body.
Sharks have been around for a really long time. The earliest fossil evidence dates back to 450 million years ago. For reference, that is 200 million years before the dinosaurs.
Sharks go through a lot of teeth in their lifetime, around 35,000 to be exact. Because their teeth aren't attached to their gums on a root like ours are, they typically lose a tooth every week. When one falls out, they simply replace the one that was lost. With the average lifespan of 20-30 years, these weekly tooth losses start adding up. Sharks usually have 5-15 rows of teeth, and whale sharks have an incredible 3,000 teeth.
Sharks do not have bones; the term “elasmobranch” translates to “fish made of cartilaginous tissue.” Their cartilaginous skeletons are much lighter than bone, and their livers are full of low-density oils, both of which help them to be buoyant. Even though they don't have any bones, they are still able to fossilize. As sharks age, they deposit calcium salts into their skeletal cartilage to help strengthen it. This causes the cartilage to fossilize just like bones do.
There are over 500 species of sharks roaming the waters. They come in all different shapes and sizes from hammerhead sharks, which have flattened and laterally extended heads, to the frilled shark, which although now extinct, had a serpent-like body.
Sharks have been around for a really long time. The earliest fossil evidence dates back to 450 million years ago. For reference, that is 200 million years before the dinosaurs.
Sharks go through a lot of teeth in their lifetime, around 35,000 to be exact. Because their teeth aren't attached to their gums on a root like ours are, they typically lose a tooth every week. When one falls out, they simply replace the one that was lost. With the average lifespan of 20-30 years, these weekly tooth losses start adding up. Sharks usually have 5-15 rows of teeth, and whale sharks have an incredible 3,000 teeth.