Relating to or resembling the crayfish or freshwater lobster, especially of the genus Astacus.
From Latin Astacus (from Greek astakos 'crayfish') plus -ian suffix. The term comes from classical Greek observations of freshwater crustaceans.
Astacian relates to crayfish, but here's the weird part: the word comes from ancient Greek, meaning that people over 2,000 years ago were interested enough in crayfish to give them a scientific name, which tells us freshwater crawdads have been important food for a very long time.
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