IS a crab in the first flush of youth, or about to kick the bucket? Even
an expert can鈥檛 reliably guess its age. But now researchers have an accurate
way to work out how old crustaceans are, which could help protect the creatures
from overfishing.
Crustaceans don鈥檛 produce any of the permanent hard parts that allow
scientists to determine the age of many other animals. So the usual way to
estimate a crustacean鈥檚 age is by measuring its size. But growth rates vary, so
this is not very accurate, says Se-Jong Ju of the University of Maryland鈥檚
Chesapeake Biological Laboratory.
Ju found that fatty hydrocarbon pigments called lipofuscins accumulate in the
brains and eye stalks of blue crabs (Calinectes sapidus) at a regular
enough rate to pinpoint their ages. Ju says it should work on any
crustacean.
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