03-15-2003, 06:17 AM
There are several ways that biologists can age fish. Judging size of fish cannot give an accurate age of fish.
Scaled fish often replenish scales as they wear out or are scraped off much the same as human skin is constantly replaced. This would mean that scales could not produce accurate annulus rings since it is unknown if a particular scale has been replaced or not.
A fishes ear is under the skin and the bone that transfers sound is called an otolith. The otolith has annulus rings(circuli) and accurate age can be determined by counting the rings under a microscope.
http://www.aquariums.state.nc.us/ata/fishage.htm
Since annual growth can vary widely an even more accurate aging of the otolith can be done by using radiocarbon dating.
A cross section of a fin can also be sliced and viewed under a microscope making it possible for a non lethal method of agin fish.
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Scaled fish often replenish scales as they wear out or are scraped off much the same as human skin is constantly replaced. This would mean that scales could not produce accurate annulus rings since it is unknown if a particular scale has been replaced or not.
A fishes ear is under the skin and the bone that transfers sound is called an otolith. The otolith has annulus rings(circuli) and accurate age can be determined by counting the rings under a microscope.
http://www.aquariums.state.nc.us/ata/fishage.htm
Since annual growth can vary widely an even more accurate aging of the otolith can be done by using radiocarbon dating.
A cross section of a fin can also be sliced and viewed under a microscope making it possible for a non lethal method of agin fish.
[signature]