The ocean is an endlessly fascinating place. We’ve only begun to scratch the surface of what’s down there, and there is some serious weirdness. Take, for example, the faceless eel researchers with the E/V Nautilus’ latest expedition spotted off the Cook Islands in the South Pacific.
While they were poking around down there in the depths — around 13,000 feet — they saw in the distance something odd. Odd is interesting, so they decided they’d better get a closer look. As it turned out, it was something called a Typhlonus nasus, better known as a faceless cusk eel.
While they certainly do appear to lack a face, looks can be deceiving. “The bulbous head is probably filled with a light ion fluid, like maybe lithium chloride,” one of the researchers explained. “That provides a positive buoyancy.”
That’s a peculiar evolutionary trait that makes a lot of sense. It takes less energy to maintain that bulbous, fluid-filled head than it does to manage a gas-filled swim bladder because of the incredible pressures down so deep. As for eyes? Yeah, they’re there.
“While these deep-sea swimmers’ bulbous faces appear to lack eyes, juveniles have been found to have tiny eyes hidden deep beneath the skin,” the researchers wrote. “Capturing these creepy critters on camera hasn’t been easy, but the deep diving capability of ROV Little Hercules means we get to meet these representatives of Cook Islands’ biodiversity for the first time.”
Eyes, at the depths that faceless cusks live at, are almost pointless. The darkness down there is nearly complete, but I suppose evolution hasn’t quite decided to entirely ditch them. As far as a mouth goes, that’s not where you’d expect one, either.
“This little fish looks amazing because the mouth is actually situated at the bottom of the animal so, when you look side-on, you can’t see any eyes, you can’t see any nose or gills or mouth,” expedition team leader Dr. Tim O’Hara told The Guardian.. “It looks like two rear-ends on a fish, really.”