Things can get pretty spooky under the sea, and the bizarre cartilaginous skeleton of a shark is no exception. Scientists Sebastien Enault and Camille Auclair of Kraniata have put together a mesmerizing skeleton of a shortfin mako shark (Isurus oxyrinchus), aka the speediest shark to grace our seas.
Enault and Auclair are masters at producing perfectly put-together skeletons of animals by cleaning bones, preserving them, and creating detailed casts. “As trained scientists with a concern for precision and a keen eye for aesthetics, we focus on anatomical accuracy and take into consideration animal behavior and movement to produce visually stunning displays of vertebrate anatomy,” they write on their website.
They’ve reconstructed the skeletons of snakes, chameleons, and budgies, to name a few, but sharks and their relatives pose the biggest challenge. Sharks are known as cartilaginous fishes, a group that also includes skates, rays, and chimeras, which means they have skeletons made out of cartilage, not bone. Being softer and less durable than the bones in our bodies, cartilaginous skeletons are difficult to preserve, making complete fossils of ancient sharks a rarity. However, the duo say that the preparation of these fishes is their specialty.

“We have developed our own technique for the preservation of delicate and often neglected structures such as labial cartilages and sclerotic rings, and have the skills and experience to prepare individual or partial structures (neurocrania, vertebrae, etc.) as well as complete skeletal specimens that are durable and ready to display,” they write.
And the results are truly remarkable, as you can see from their fascinating yet slightly haunting rendition of a mako shark. These sharks are often described as the cheetahs of the sea, moving at speeds of up to 72 kilometers (45 miles) per hour. Their speed and agility make them exceptional hunters, efficiently snapping up smaller fish and squid.

Enault & Auclair-Kraniata Osteology
Despite being found across the oceans, the shortfin mako is currently listed as endangered on the IUCN Red List. Like all sharks around the globe, they are at risk of being fished for their fins, which are used to make shark fin soup, an Asian delicacy. They often fall victim to fishing gear too, becoming accidental bycatch.
Conservationists are working hard to change attitudes towards shark fin soup, encourage the consumption of alternatives like “faux fin soup”, and ensure better protection for the species. Let’s hope these remarkable fish can cling on so that we have more than just their skeletons in the years to come.
Take a look at some more of Kraniata's work below.