Sharks & Skeletons: A Spooky Peek Inside the Ocean’s Top Predators
October is here, and with Halloween just around the corner, we’re all about skeletons—but today, we’re diving into something even spookier: shark skeletons! These ocean-dwelling predators might not be as bone-chilling as the skeletons we hang on our porches, but their anatomy is full of tricks (and a few treats). Let’s take a closer look at what’s lurking beneath a shark’s tough exterior.
Cartilage: A Skeleton with a Twist
Our hard skeletons are made of bones, 206 to 213 bones to be exact, from our rattling skulls to our toes. A shark’s skeleton is made of 200 to 400 structures that form a skeleton with a skull, spine, and fins.
Figure: Sandbar shark (Carcharhinus plumbeus) skeleton
Shark skeletons are made of specialized cartilage, which is lighter and more flexible than bone. This gives sharks an eerie advantage, allowing them to be more agile, silent, and swift in the water – moving with spine-tingling speed. We have cartilage in our ears and nose, and it protects the ends of our bones. But a shark’s cartilage is different from ours with mineralized (calcified) tiles along the outside to make it harder and stronger.
Figure: Histologic image demonstrating the mineralized (dark purple) tiles called tesserae along the edge of the cartilage (light purple) in the skeleton of a shark
Sharks may not be the skeletons of Halloween lore, but their eerie, flexible skeletons and powerful bodies make them imposing predators of the deep. They are the ghosts of the ocean, designed for stealth, speed, and survival. So, this October, while you’re carving pumpkins and putting out spooky decorations, don’t forget to give a nod to the ocean’s very own creatures of the night: sharks.
Figure: Radiograph (xray) of an adult horned shark
About OCEARCH
OCEARCH is a global non-profit organization conducting unprecedented research on our oceans’ giants in order to help scientists collect previously unattainable data in the ocean. Our mission is to return our world’s oceans to balance and abundance through fearless innovations in critical scientific research, education, outreach, and policy using unique collaborations of individuals and organizations in the U.S and abroad. OCEARCH is recognized as a world leader in generating scientific data related to tracking (telemetry) and biological studies of keystone marine species such as great white sharks, tiger sharks, and more. OCEARCH provides a free open-sourced Global Shark Tracker® and app that allows scientists, educators, and fans alike to learn about the never before documented movements of our ocean’s animals. The non-profit organization provides a free STEM education curriculum that enables students to learn STEM skills while promoting environmental awareness. OCEARCH’s research is proudly supported by Costa Sunglasses, YETI, SeaWorld, Yamaha Rightwaters, Ulysse Nardin, Cisco Brewers, Jefferson’s Bourbon, Landry’s, and our academic home Jacksonville University. Learn more at ocearch.org.
