:Metopus rex

{{Short description|Species of single-celled organism}}

{{Taxobox

| domain = Eukaryota

| unranked_regnum = SAR

| unranked_superphylum = Alveolata

| phylum = Ciliophora

| subphylum = Intramacronucleata

| classis =

| ordo = Armophorida

| familia = Metopidae

| genus = Metopus

| species = M. rex

| binomial = Metopus rex

| binomial_authority = Vďačný & Foissner, 2016

}}

Metopus rex is a species of metopid first found in soil from the Murray River floodplain, Australia. This species can be distinguished from its congeners by its large body size and the shape of the macronucleus. M. rex exhibits up to 30μm-long endosymbiotic bacteria.{{cite journal|last1=Vďačný|first1=Peter|last2=Foissner|first2=Wilhelm|title=A huge diversity of metopids (Ciliophora, Armophorea) in soil from the Murray River floodplain, Australia. I. Description of five new species and redescription of Metopus setosus Kahl, 1927|journal=European Journal of Protistology|volume=58|pages=35–76|year=2016|issn=0932-4739|doi=10.1016/j.ejop.2016.12.001|pmid=28131035}}