unknown invertebrate larva

an actinotroch larva? (Phylum Phoronida)

Collected: April 2006, 2-4 km off of Assateague, VA. depth of 10 using an epibenthic sled fitted with a plankton net (363 micrometer Mesh).

The specimen shown here MAY be the actinotroch larval stage of a phoronid worm, although this identification requires verification by an expert on this group (if we can find one). One diagnostic characteristic is the group of tentacles arising below the ‘head’ (the upper left of this photo). Absence of segmentation and setae rules out polychaetes.

Phoronids are small, inconspicuous worms that live in burrows on sand or mud and feed with a specialized ciliated structure– the lophophore.

Phoronids produce several distinct larval forms that appear briefly in the plankton before settling to the bottom. Phoronid larvae are seldom encountered in the nearshore plankton.


Collected by: Bill Johnson, Goucher College.