''Flabesymbios commensalis'' is a

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

of marine worm that lives in

sea urchin Sea urchins or urchins () are echinoderms in the class (biology), class Echinoidea. About 950 species live on the seabed, inhabiting all oceans and depth zones from the intertidal zone to deep seas of . They typically have a globular body cove ...

spikes. According to recent research, ''F. commensalis'' has a two-color body and lives on urchins in the genus ''

Strongylocentrotus ''Strongylocentrotus'' is a genus of sea urchins in the family Strongylocentrotidae The Strongylocentrotidae are a family (biology), family of sea urchins in the order (biology), order Camarodonta. Genera References Strongylocentroti ...

''. It has been found along the Pacific coast of North America.

References

Animals described in 1909 Annelids of the Pacific Ocean Terebellida {{annelid-stub