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Deepseawaters
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Sea FAQ How is the age of a fish determined?
How is the age of a fish determined?
Mainly
by two methods: Growth "rings" on scales, and/or ringlike
structures found in otoliths (small bones of the inner ear),
are examined and counted. The rings correspond to seasonal
changes in the environment and can be compared to the annual
rings of tree trunks. A series of fine rings are laid down
in scales for each year of life in summer, the rings grow
faster and have relatively wide separations; in winter, slower
growth is indicated by narrow separations between rings. Each
pair of rings indicates one year. Because scale rings are
sometimes influenced by other factors, scientists often use
otoliths, whose ringlike structures also indicate years of
life.
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