Fish have 'Age' rings just like trees. To prove this you will need: What To Do: - Collect scales from some fish at
your local market or from your fridge if there's any in there.
- Place
a dried scale on the paper.
- Use the microscope or magnifying glass
to look at the ring pattern on the scale.
- Count the wide, lighter
coloured rings, and the thin, darker coloured rings.
The number of rings on a fish scale are equal to the age of
the fish. Some years, the fish will have grown quickly, and some years it
will have grown slowly. This is normally due to environmental
factors. As a fish grows larger, its scales do
too. They grow by adding rings around the outside edge of the scale, similar
to the way rings look on the trunk of a tree. A scale can be added anywhere
from 2 to 20 rings per year. More rings mean more growth. Small reef fish
usually live for a few weeks or months, whereas other fish such as the
sturgeon can live for 50 years or more.
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