epizoic
/ˌɛpɪˈzoʊɪk/
adjective
- Living on the surface of an animal, typically as a parasite or commensal.
- The epizoic algae growing on the turtle's shell did not harm the turtle.
- Some mites are epizoic, living on the skin of birds and mammals.
- Barnacles are epizoic organisms that attach themselves to whales and other marine animals.