Kyoto Oceanic Centre announces new prawn marking technique
JAPAN
February 07, 2002
http://www.fis.com/
The Japan Fisheries Research Station has awarded an honorary commendation
for a new prawn marking technique called the 'tail limb cut method,' as it
has proven to be effective in evaluating seeded items. The conventional
marking technique for farmed fish is tagging. However, this method is not
appropriate for tracing prawn for a long period as the crustacean moults at
an early stage in its cycle. The alternative, the tail cutting method that
identifies specimens by the length difference between a cut limb and a
normal limb, is more often adopted, but the difference disappears after
repeated moulting.
The 'tail limb cut marking method' identifies items by placing a pigment
between the cut limb that has grown back after moulting and a normal limb.
It is known that dark red pigments exist inside prawn limbs, and if one is
cut, the pigment fades even after the limb has grown back. Such low
colouration can be identified even in mature specimens.
The method, developed by Kyoto Oceanic Centre, was presented before 300
researchers at the Second International Symposium on Stock Enhancement and
Sea Ranching on 29 January.
Already, the method has proven to be effective for marking prawn in the
Ariake and Inland seas and could be used in various parts of the world.
By Haruo Chiba
FIS Japan