A burrowing wormlike marine animal of shallow waters. Its body consists of a proboscis, a collar, and a long trunk with gill slits, and contains a structure resembling a notochord.
Class Enteropneusta, phylum Hemichordata
‘The cilia on the larvae of acorn worms capture algae.’
‘Pterobranchs as very different from acorn worms; they form colonies in which the individuals are interconnected by stems, or stolons.’
‘An acorn worm isn't much more than a thin, cylindrical bag with a head and collar resembling an acorn.’
‘These coils often seen on the sand have been processed by the acorn worm.’
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