Marine biologists from the Monterey Bay Aquarium Research Institute (MBARI) and the Monterey Bay Aquarium stumbled upon a pretty neat surprise when they were exploring the deepest parts of the ocean.
They were remotely operating an underwater vehicle off the coast of California to collect jellyfish for the aquarium’s next exhibit when they spotted a remarkable fish—a Macropinna microstoma.
According to GEO, such an encounter is very rare. As a matter of fact, in over 5,600 successful dives and with more than 27,600 hours on video, biologists have only encountered this fish a total of nine times—incredible!
What is this strange fish?
Macropinna microstoma, also known as the barreleye fish, lives in the twilight zone of the ocean—at depths of 600 to 800 metres. It is about 15 cm long and feeds on zooplankton like crustaceans and siphonophores.
What sets this fish apart from the rest is that it has a completely transparent head and as a result we can see everything inside, including its big green eyes.
Surviving in the deep
To survive in such harsh conditions, creatures that live in secluded and dark areas often evolve in very strange ways, but the barreleye fish has got to be one of the most bizzare.
For one, the two slits that are present on its face (where you’d expect the eyes to be) is actually where its olfactory organs are located. And the eyes? Well they’re behind its face and they form two bright green ‘orbs that look up from its head.’ MBARI explains on their website:
This ‘deep-sea fish can see through their own foreheads.’
In 2009, MBARI researchers showed that fish can turn their eyes forward to see their food when they eat. Before that, scientists thought its eyes were fixed upwards. The researchers believe that the fish hovers under the tentacles of the siphonophores to steal food.