In this bizarre video footage, a female Indo-Pacific dolphin is seen exhaling or leaking air from her left eye socket.
In case you might not be familiar with dolphin anatomy, dolphins aren’t meant to breathe through their eyes. In your traditional dolphin body, there is only one connection from the lungs to the outside world, and that’s via the blowhole. Everything in the dolphin’s skull is designed to make the transfer of air, in those brief moments when a dolphin’s head breaks the surface of the water, as safe and efficient as possible. Evolution even designed anatomical structures to block the connection from a dolphin’s mouth to its lungs just to make it that much harder to either accidentally inhale water, or inadvertently leak air. With such an exquisitely designed closed system, how can we explain this strange video footage?
A team of dolphin scientists, including dolphin cranial specialists (yes that’s a thing), analyzed the above video and concluded that there must be something quite abnormal – and rather sinister – happening in this poor dolphin’s head. Dolphins have a number of air sac and other air-filled structures in their skull, including a sinus-like structure adjacent to their eye sockets. In a normal dolphin, there is an air-tight barrier of blood vessels and fibrous muscle tissue that separates this sinus structure from the eye-socket, with just enough room to allow the ocular nerve to pass through en-route to the brain. This flexible tissue-wall expands and contracts as the dolphin’s nasal-sacs fill with air. But for the poor dolphin in this video, there is some sort of hole or leak in this tissue-wall, which causes the expanding air to rush into the eye-socket as the animal rises to the surface. How did this hole get there? Here are the scientists’ two best guesses:
1) A worm-like lung-parasite (i.e., a nematode) ate its way through the tissue-wall.
2) The barb from the tail of a stingray stabbed the dolphin in the eye and punctured the tissue-wall.
Either of those options are tragic and/or gross, not to mention uncomfortable. So will this dolphin die from this bizarre problem? Maybe not. The two biggest risks for this dolphin are that it can’t keep enough air in its lungs to stay under water long enough to find food, or that the hole might actually let water rush into its lungs if it dives too deep. I guess the main lesson here is that if you suspect you have lung nematodes and are planning a diving holiday this summer, please visit your physician to see if the nematodes have eaten a hole in your sinus tissues. Maybe that’s not really the main lesson. But it is a lesson.
You can read more about this situation in the original article:
Dudzinski, K. (2013). Short Note: Air Release from the Left Orbit of an Indo-Pacific Bottlenose Dolphin (Tursiops aduncus): Symptomatic and Anatomical Aspects Aquatic Mammals, 39 (1), 97-100 DOI: 10.1578/AM.39.1.2013.97
PDF at this link.
The video footage was filmed by John Anderson of Terramar Productions.
I actually didn’t notice this until a reader pointed it out to me, but that guy in the video is reaching out to try to touch the dolphins. Not cool bro! It is strongly advised to not touch wild dolphins in these kinds of situations. No chasing, no feeding, no touching – just observe silently and try your hardest not to bother wild dolphins, kthanks!