did you know that there's a creature
with a completely transparent forehead
the barrel eye fish gets its name from
the two rotating green barrel lenses
which allow it to observe its prey even
from below
it's just one of many fascinating
species that researchers from the
monterey bay aquarium research institute
filmed when exploring the depths of the
ocean
what we know as the deep sea begins
around 200 meters below the surface of
the ocean
here light starts to fade away the
temperature drops
and pressure rises 4 000 meters down
the temperature hovers around freezing
and there's no sunlight whatsoever
living light is virtually the key to
existence
and there are many bioluminescent
creatures around
from the surface all the way to 4 000
meters deep
three quarters of ocean dwellers can
produce their own light
until recently it was impossible to
collect
living bioluminescent creatures from the
deep but mbari's remote submersible
known as doc ricketts is equipped to do
just that mbari is a pioneer of deep
ocean exploration in the control room
thousands of meters above doc ricketts
steve and the crew
navigate around alien-like life forms
in the dark depths there are no edges
no boundaries nowhere to hide
both predators and prey have had to
develop some
extraordinary strategies to stay alive
and many do so with the help of light
what the team finds is amazing
viperfish
and vampire squid even with it
another rare sighting was the barrel eye
fish
it has extremely light sensitive eyes
that can rotate within a transparent
fluid-filled shield on its head the eyes
point upward when the fish is looking
for food overhead
and forward when it's feeding the two
spots above the fish's mouth
aren't eyes these are olfactory organs
called nairs which are the equivalent of
human nostrils
nearby the team spotted a cockeyed squid
has one normal eye and one strange
upward looking eye
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the scientists findings also include one
of the few dragonfish
ever to have been seen alive
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which is also one of the even fewer to
have been captured
unharmed
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yes
to have any hope of observing these
creatures light-making abilities
the research team needs to bring them to
the surface
gentle suction and remote controlled
canisters are used
to delicately scoop up the rare animals
once they arrive at the ship thousands
of meters above their normal environment
there's no time to waste the enormous
pressure change is likely to cause
any bioluminescence to disappear
the race is on to try to observe these
abilities and understand their functions
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most of the creatures don't glow
continuously because making light uses
extra energy and can attract
predators in some species
it seems to be a defense tactic like the
circular flashes
of the atala jellyfish
or the rippling light waves of the
baroque jelly
in other species like this viperfish
light isn't just used for defense
but also to lure in prey
pyrosims use light to communicate within
and between
colonies the team's experiment shows
that as one colony begins to glow its
neighbors light up in response deep sea
animals use bioluminescence for three
primary reasons
to find food to avoid being eaten and
to find a mate
for decades the human eye worked far
better than
any video camera at recording the subtle
light of deep sea life
but as dr haddock says camera
sensitivity has recently begun to rival
that of the human eye
and will eventually surpass it
scientists are sure that this advance
will let them document light
previously seen only fleetingly as well
as help discover new forms of luminous
display
the ocean isn't the only place with
fascinating creatures
so stay tuned for our next video and
explore the beauty of our planet