Definition of Spio 

: a widely distributed genus (the type of the family Spionidae) of small burrowing marine polychaete worms without tentacles or palps but with enlarged dorsal cirri acting as gills

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History and Etymology for Spio

New Latin Spion-, Spio, perhaps from Latin Spio, one of the Nereids, from Greek Speiō

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to reject or criticize sharply

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