Klik her for at se PDF'en - Air Greenland

Other creatures than the hatchet fish use light for camouflage.
For example, the ten­armed squid –bobtail squid – that hides on
the seabed, while it cultivates special, light­producing bacteria.
When the amount of bacteria is sufficient, its light is so powerful
that the squid can use it as camouflage when it hunts small
fish and crustaceans with its harpoon­like tentacles.
One of the most sophisticated predatory fish in the deep sea is
the “Northern stoplight loosejaw”. Its name certainly does its
unique characteristics justice, partly because it can open its jaw
180 degrees and partly because it has a yellow and a red organ
on its head that can emit light.
Most of the creatures in the deep sea are only able to see in blue
light so the Northern stoplight loosejaw has a light for finding
food that is invisible to prey. Some of the creatures it preys on
have developed eyes that can see the red and yellow light and
scientists indicate that evolution in this case is something of an
arms race, where predator and prey continually develop and
adapt to each other’s characteristics.
Greenland shark
As mentioned previously, most of the organisms in the deep sea
have discovered the advantage of using light and this is true of
a giant of the deep sea, i.e. the Greenland shark. The Greenland
shark is up to seven metres in length and can weigh around
1100 kg, which makes it one of the biggest predatory fish in the
world.
Scientific knowledge of these mysterious sharks is limited, but
there are many theories about its way of life. Water fleas often
live attached to the shark’s eyes spoiling its vision, but as the
flea emits lights, it is possible that this is not detrimental to
the shark’s survival. Scientists believe the shark uses the lightemitting
fleas as bait, in the same way the deep­sea anglerfish
uses its fishing rod. Instead of using its sight, when the prey
has been lured close to the shark, the shark can use its electrical
sense to localise the exact position of the prey. This sense is
characteristic for many sharks and rays.
The importance of the water fleas attached to the eyes of the
Greenland shark is, however, not scientifically proven, since
this mysterious fish lives in places where scientific studies are
difficult to carry out. In addition to sensing electrical currents,
the Greenland shark has a good sense of smell, which it uses to
find dead creatures at the bottom of the sea. In addition to the
shark’s eyes, its age is also a mystery to scientists. Because of
the cold water, the low metabolism of the creature and a single
re­capture of a tagged fish (that showed growth of 8 cm in 16
years), several scientists believe that these giants can become
extremely old. Measurements indicate that ages of up to 200
years for the biggest individuals could be possible and thus the
Greenland shark is one of the oldest vertebrates on earth.
Suluk #03 Air Greenland Inflight Magazine 2012 19