sentence: Protozoan parasites are also ubiquitous.
sentences_before: A huge number of species are parasitic. A check list of British insects'. Also, there are several other invertebrate phyla which are wholly or largely parasitic. Flatworms and roundworms are found in virtually every wild species of vertebrate.
sentences_after: Hence parasitism is almost certainly the most common feeding method on Earth.
concept_name: protozoan parasite
headings: Parasitism Biological context
categories: Co-evolution