Intertidal Creatures

Plumed Worm Plumed Worm

What are they?

The muddy and sandy zone that occurs along beaches and back bays between the high water mark and the low water mark is known as the intertidal zone. This can be a tough place for any creature to live, requiring the ability to survive in saltwater while the tide is in, then survive in much drier conditions while the tide is out - to say nothing of the trials of surviving the wave action during rising and falling tides. Creatures of these zones include a number of species that are covered elsewhere on this site, such as crabs, shrimps and various shellfish, so this section serves as a catch-all for anything not included on those pages.


This is a mixed bag of species, many of which are small or elusive and thus some are more easily identified by sign of their presence, or by their 'homes' rather than by the creatures themselves. Work through the pictures and text below for clues to identification.

  Plumed Worm     Diopatra cuprea

An abundant species of intertidal waters in the backbays and along the bayshore. Plumed worms are large (up to one foot long) worms that have seven antennae on their heads and a 'plume' of gills just behind the head. Finding them would involve digging into the mud when the tide is out, but they make their presence obvious by making tubes within which they live. The top of these tough, membranous tubes project some two or three inches proud of the surface and are encrusted in various objects that the worms can find nearby - usually including pieces of seaweed, broken shell and the like.
Plumed Worm Plumed Worm
Detritus-covered tubes
Detritus-covered tube