Orca's dorsal fin seems just preposterously large, but why? 🤔 . Actually it's the biggest dorsal fin of any mammal and can grow up to a stunning 1,8m! 🤯 . It acts a keel on the boat - balancing and providing sideways support. Some studies suggest that it also acts as cooling device - keeping the fin above the water during long swims might prevent the animal from overheating! 🧊 . As every fin, they don't have any bones, just collagen. That's why they sometimes collapse and bend! Especially prevalent with captive orcas, but also present in nature, the phenomenon is not clearly explained 🤔 . Some researchers say it's due to poor nutrition and stress, others that it's a natural reaction to lack of long distance swimming. The conclusion is unclear, but it's not like we need one more reason to not keep orcas in tiny tanks for entertainment. There is plenty of them already... . 📸 Check out more photos from @ericaustinyee . 👉 Follow @freshnsaltyeco to get a clue in the blue! . . . #clueintheblue #freshnsalty #orcagang #orcapod #orcasofinstagram #killerwhales #apexpredator #grandmaknowsbest #wildlifephotographer #marinebiodiversity #oceandecade #OnlyOneOcean #fishphotography #marinecreatures #marinewildlife #underwaterimages #uwphotographer #uwphoto #divingphoto #marinebiology #oceanconservancy #wildlifephotography #underwaterphotography https://www.instagram.com/p/CT4i_NuK8u4/?utm_medium=tumblr