Adjective
biotrophic (comparative more biotrophic, superlative most biotrophic)
(biology) Describing a parasite or symbiont that needs its host in order to stay alive.
An example of a biotrophic relationship would be a tick feeding on the blood of its host. Source: Internet
This genome analysis revealed the dual saprotrophic and biotrophic lifestyle of the mycorrhizal fungus that enables it to grow within both soil and living plant roots. Source: Internet