Life in the ocean deep can get pretty wacky. However, among all of the seemingly alien lifeforms that we’ve discovered down there, there is perhaps one who tops the oddity charts: the barreleye fish. Found at depths most light can't reach, these truly bizarre animals are equipped with a see-through head, allowing their eyes to effectively look out of the sunroof as they navigate the pitch-black waters.

Don’t believe us? Just check out the below video from the Monterey Bay Aquarium Research Institute (MBARI) which shows a barreleye fish doing what barreleye fish do BEST in stunning definition (for the fully immersive experience, we recommend popping on the X Files theme tune as you do).

Captured using a remote-operated vehicle (ROV), it shows a barreleye fish (Macropinna microstoma) cruising off the coast of California. Such videos call for ROVs as barreleyes live at a casual depth of 600 to 800 meters (2,000 to 2,600 feet), well beyond terrestrial human’s reach. The ROV was on the prowl as part of an expedition tied to the Rachel Carson research vessel.

"MBARI’s remotely operated vehicles Ventana and Doc Ricketts have logged more than 5,600 successful dives and recorded more than 27,600 hours of video—yet we’ve only encountered this fish nine times!" Reads the video's caption.

As for locating the eyes of the barreleye, the vision balls aren’t actually those two indentations you see in the convention eye position, but actually the glowy green balls sitting slightly further back. The circles at the front are actually olfactory organs that can “smell” chemical cues in the water.

The function of the eyes’ strange positioning, MBARI says, is to spy prey above which they’ll sometimes steal from the dangling tentacles of siphonophores. As ultra-sensitive tubular eyes, they are incredibly well adapted for spotting the silhouettes of edible animals against the minuscule amount of light that travels to such depths.

At one point it was thought the barreleye’s eyes were constantly to the sky, but it’s since been established that they can roll to face forwards when eating. The perks of having a see-through head include being able to look through the transparent shield your eyes sit in and effectively see through your own mouth. Handy when you’ve got a mouth as small as the barreleye’s.

So, now that you’ve seen one in action and heard the facts, what do you reckon? Barreleye fish: alien, fish, or submarine operated by that little brain alien from Men In Black?