Acorn Worm

Acorn Worm

The Acorn worms or Enteropneusta are a hemichordate class of invertebrates consisting of one order of the same name. They are closely related to the echinoderms. There are about 90 species of acorn worm in the world, the main species for research being Saccoglossus kowaleskii.

All species are infaunal benthos that either may be deposit feeders or suspension feeders. Some of these worms may grow to be very long; one particular species may reach a length of 2.5 metres (almost eight feet), although most acorn worms are much, much smaller.

One genus, Balanoglossus, is also known as the tongue worm.