Science Matters →

What’s Scarier Than a Shark With One Head?

shark fin in the water

Okay science lovers, it’s time to get into the Halloween spirit and explore that overlap of scary and scientific. What’s scarier than a shark with one head?

We love the topic of sharks. We love chatting about climate related regional shark issues. We love chatting about walking sharks (yes, you read that correctly, walking...sharks.) We love chatting about shark-related technology. https://smv.org/learn/blog/post/question-your-world-can-sharks-walk

A two headed shark was discovered off the coast of India earlier this month. A fisherman noticed this unusual creature in his catch and shared some pictures online of what turns out to be a two headed juvenile spade nose shark. These particular sharks only grow to about two to three feet in length at full maturity and are generally considered totally harmless to humans

Okay, but what about this two headed business? This shark is bicephalic, meaning two headed. This has been known to occur in many species for different developmental reasons. Either one embryo can split incompletely, or two embryos can partially fuse. Both situations arise from genetic or environmental causes. Scientists have observed strange development in some animals from foreign objects, like microplastics interfering inside a forming embryo. Pollution impacts like chemical interference could also lead to a two headed situation. And of course natural cases have also been known to happen in humans, deer, snakes, fish, salamanders, and other animals. 

However, we’ll never know what caused bicephaly in this two headed shark because the fisherman ultimately decided not to keep it and tossed it back into the ocean. That’s right folks, it could still be out there!

Okay, so you know what’s scarier than a two headed shark? A THREE HEADED SHARK!! Don’t worry, there are no accounts of three headed sharks yet, but tricephalic or three headed occurrences have also been observed by science, but that’s another tail all together.