David Attenborough’s famous BBC series Blue Planet 2 gave the world an insight into just how little our oceans had been explored. During a special extended version of the programme, cameras revealed how a team of scientists used a Triton submarine, capable of reaching depths of 1,000 metres, to explore areas never visited before. Descending into the “twilight zone”, depths between 200 and 1,000 metres deep, the group uncovered some amazing finds.
Video footage shows the moment the team captured one creature that left quite an impact on them.
Sir David said during the 2018 documentary: “The deep ocean is as challenging to explore as space – we know more about the surface of Mars than we do about the deepest parts of our seas.
“As we descend into the deep, the pressure increases and the lights from above all but disappear.
“We enter an alien world – the twilight zone – a sea of eternal gloom.
“Survival here means making the most of every last glimmer.”
The researchers then stumble across the barreleye fish, also known as the spook fish due to its bizarre facial features.
Found in waters between 400 and 1,000 metres deep, it was the first time anyone has managed to get quite as close.
Sir David, 92, continued: “This is the barreleye – a fish with a transparent head.
“It is filled with jelly so it can look up through its skull.
“We now know that the twilight zone is a refuge for an incredible 90 percent of all fish in the ocean.”
It comes after the team revealed an equally bizarre creature 200m below the surface.
The Histioteuthis heteropsis, also known as the Strawberry Squid, is a species of cock-eyed squid that gets its name from its unique facial features.
The cephalopods have two different kinds of eyes, one being small and blue, while the other is large and yellow.
Sir David revealed during the same show: “What we found was a squid, but this is one that only lives here.
“Its right eye looks permanently downwards, but its left eye is much bigger and trained upwards to detect the silhouettes of prey swimming nearer the surface.
“No wonder it’s nicknamed the cock-eyed squid.”
The size of its upwards-facing left eye increases its sensitivity to the faint sunlight shining down from the surface.
In the murky waters, bioluminescent creatures – like the cock-eyed squid – camouflage themselves to escape danger.
This involves masking their shadows by emitting light that matches the intensity of the downwelling surface rays.
The squid’s yellow lens, common in some species of deep-sea fish, helps it pierce through this camouflage so it can detect bioluminescent prey such as shrimp.
The right eye, on the other hand, scans the waters below for bioluminescent flashes emitted by lurking predators or prey.