Intertidal Invertebrates of the Monterey Bay Area, California

Compiled & photographed by Gary McDonald, Long Marine Laboratory, University of California, Santa Cruz

Description: This is the only protozoan which is likely to be seen with the naked eye in the intertidal. It is spherical, with a transparent shell through which may be seen the light brown protoplasm. It may be found in the holdfasts of algae or surfgrass, or nestled amongst hydroids, bryozoans, etc. Because of its shape and color, it may easily be mistaken for an egg or fecal pellet.
Size: 1-3mm, up to 5mm in diameter.