FLATWORMS Phylum PLATYHELMINTHES

This group includes the parasitic flukes and tapeworms, but further focus falls upon the free-living flatworms. “Dorso-ventrally challenged,” or flattened top to bottom, these primitive, unsegmented flatworms slip along the substrate upon countless tiny cilia (hairs). The photograph shows the white flatworm (PL7). In each species, a simple or branched digestive tract is serviced by only one opening—the mouth doubling as the anus.
At least 126 species of free-living flatworms dwell in the marine waters of the Pacific Northwest, and doubtless many more remain to be discovered and recorded.

PL1. SPOTTED FLATWORM

Eurylepta leoparda

PL2. GIANT FLATWORM, giant leaf worm, large leaf worm, leaf worm

Kaburakia excelsa, Cryptophallus magnus

PL3. SADDLEBACK FLATWORM

Notoplana sanguinea, Notocomplana sanguinea

PL4. INTERTIDAL FLATWORMS, including tapered flatworm, brown flatworm, common flatworm, leaf worm

Notocomplana spp., including Notocomplana actinicola, Notoplana acticola, Leptoplana acticola?

PL5. CALIFORNIA FLATWORM

Stylochus californiensis

PL6. GREEN FLATWORM

Phylloplana viridis, Triplana viridis, Stylochoplana viridis

PL7. WHITE FLATWORM, polyclad worm

Pseudoceros luteus, Ambylceraeus luteus

PL8. STRIPED POLYCLAD WORM, polyclad worm

Eurylepta californica

PL9. COMPOUND TUNICATE FLATWORMS

Pseudoceros canadensis/Stylostomum sanjuania

PL10. BIVALVE FLATWORM

Pseudostylochus ostreophagus, Koinostylochus ostreophagus

PL11. PINK PARASITIC FLATWORM

Kronborgia pugetensis

PL12. PAPILLOSE FLATWORM

Holoplana californica