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Ink
In the mantle cavity, an ink gland is
also present which often makes a black pigment that can squirted out a
little at a time and create a dark cloud in the water. This is used to
cause confusion while fleeing from an attacker or when the cuttlefish
is disturbed.
Camoflage
The pigment cells on the cuttlefish are
masters at changing colour. With its white, green or brown stained skin,
the cuttlefish is well disguised amongst other bottom living organisms
and be difficult to detect. It is thought that the colour changes are
triggered by a certain behaviour, e.g. fear, etc.
Useful creature
The cuttlefish skeleton has a long history
as a medicin against illness, e.g. anaemia, asthma, eye and skin diseases.
The powdered skeleton has also been used for polishing teeth, gold and
silver. Lately, it has been used as a calcium addition for caged birds
that can peck on the porus material. Sepia is a dark brown colour, with
a slight tone of grey and purple. In Asia, it was extracted from the ink
gland of cuttlefish as long ago as 2 600 B.C. It has also been used
as a watercolour to draw and paint with. The advantages with sepia were
that it did not damage the papyrus or parchment, the disadvantage was
that it was not water resistant.
Fishing
The cuttlefish is an
important species that is fished from the Bay of Biscay to
west Africa and in the Mediterranean. They are usually
caught with relatively simple tackle, e.g. traps, lines and
trawls. In the Mediterranean, about 10 000 tons are
landed annually.
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