The ocean’s apex predator has fascinated humans for centuries. With more than 500 different species swimming the deep blue sea, there are many questions about this magnificent creature. One of the most commonly asked is: how many bones are in a shark?
While most people believe that how many bones are in a shark, this is not true. Instead of bone, sharks are made from cartilage, which is a flexible and lightweight tissue that also makes up our ears and the tips of our noses. Cartilage allows sharks to move more quickly and efficiently in the water.
Unveiling the Skeleton Secrets: Do Sharks Have Bones or Cartilage
In addition, cartilage is about half as dense as bone, so sharks can move with less effort and not sink as easily. Their cartilaginous skeletons also protect their internal organs from damage.
Sharks have a spine made from 45-50 cartilage segments that extend from their skull to the base of their tail fin, along with ribs, 6-8 pairs of rod-like cartilage sections for supporting their pectoral and pelvic fins, and jaws, which are supported by 5-6 pairs of rod-like cartilage sections. They also have a cranium that protects their brain and a series of gill arches to support their gills.
Sharks are part of the class of fish known as elasmobranchs, which include other cartilaginous fish like stingrays and sawfish. They extract oxygen from the water through their gills and have big livers filled with low-density oils to aid in flotation, reports NOAA. Because they do not have bones, they cannot grow or repair damaged areas of their body as mammals and most land vertebrates can.