David Attenborough’s famous BBC series Blue Planet 2 gave the world an insight into just how little our oceans had been explored. During the second episode of the programme, cameras revealed how a team of scientists were able to head 1000m below the ice of Antarctica for the first time ever. Using a Triton submarine, researchers captured incredible footage as they entered the “twilight zone”.
The programme revealed a strange, long creature floating through the water, that captured the interest of the team.
Sir David said in 2017: “The sunlight fades and the seas darken.
“Here in the Pacific, 200m down, we enter an alien world – the Twilight Zone – a sea of eternal gloom.
“There are strange creatures here – a pyrosome – a tube of jelly two metres long that dwarfs a visitor from above, an oceanic whitetip shark.”
The team took a boat out to the waters around Antarctica (Image: BBC)
A Triton submarine was sent 1000m below the water (Image: BBC)
There are strange creatures here – a pyrosome – a tube of jelly two metres long that dwarfs a visitor
Pyrosomes are free-floating colonial tunicates that grow up to 60ft in length.
They are made up of hundreds to thousands of individuals known as zooids, commonly known as “sea pickles”.
Sir David continued to describe the alien-like scene as he spotted more unusual creatures.
He added: “Only a tiny amount of light filters down this far.
“Survival here means making the most of every last glimmer.”
The pyrosome was uncovered by the team (Image: BBC)
The bizarre creature is bigger than a shark (Image: BBC)
As the narrator noticed a nearby swordfish, he added: “This swordfish has eyes as big as tennis balls to help it see in the dusk.”
During the same series, the team also ventured into an area known as the “midnight zone”, some 1,000 metres below the surface.
Here, they were stunned by “alien-like creatures”.
Sir David said in 2017: “We go deeper, into the world of perpetual blackness below – the Midnight Zone.
“Two-thirds of a mile from the surface, beyond the reach of the sun.
The team also uncovered a strange “alien-like” creature (Image: BBC)
The bizarre creatures lit up the ocean (Image: BBC)
“A giant black void larger than all the rest of the world’s habitats combined.
“There’s life here, but not as we know it.”
Suddenly, the waters were filled with bright neon lights, startling the crew and Mr Attenborough.
The 92-year-old presenter detailed: “Alien-like creatures produce dazzling displays of light.
“Nearly all animals need to attract mates and repel predators but this language of light is so widespread here that these signals are probably the most common form of communication.
“Yet we still know little about them.”
Then, 200m before reaching the surface, they uncovered the Histioteuthis heteropsis, also known as the Strawberry Squid.
The cephalopod, a member of the cock-eyed squid family, gets its name thanks to its bizarre facial features.
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 cock-eyed squid has two different eyes (Image: BBC)
Its second eye looks down below (Image: BBC)
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.