An organism associated with another in symbiosis; a symbiotic organism.

1. An organism that is associated with another one in symbiosis.
2. A special application of this term refers to tiny sea organisms which live on the mouthparts or mouth hairs of the Norwegian lobsters where they feed on the leftovers from the lobsters' meals and they seem to be harmless to their hosts.

They were discovered in 1995 by Danish scientists Reinhardt Kristensen (professor, curator of the Natural History Museum of Denmark) and Peter Funch (Associate Professor, Ecology & Genetics, Aarhus University, Denmark) and they were classified as Cycliophora, a new phylum of creatures.

Symbions have no legs, but each one keeps itself in place with a short stalk ending in an adhesive disc that attaches to the host lobster's mouth hairs.

Apparently there are two other species of symbions: one lives on American lobsters, and another, which may not be a distinct species, lives on European lobsters.

The Latin term is Symbion pandora.