{{Short description|Family of flagellate eukaryotes}} {{Automatic taxobox | image = Euglena mutabilis - 400x - 1 (10388739803) (cropped).jpg | image_caption = ''Euglena mutabilis'' | taxon = Euglenaceae | authority = Dujardin, 1841 | type_genus = ''Euglena'' | type_genus_authority = Ehrenberg, 1830 | subdivision_ranks = Genera | subdivision = *''Colacium'' *''Cryptoglena'' *''Euglena'' *''Euglenaformis'' *''Euglenaria'' *''Monomorphina'' *''Strombomonas'' *''Trachelomonas'' }} '''Euglenaceae''' (also known as '''Euglenidae''') is a family of flagellates in the phylum Euglenozoa. The family includes the most well-known euglenoid genus, ''Euglena''.<ref name="Kostygov_2021">{{cite journal | pmid = 33715388 | pmc = 8061765 | doi = 10.1098/rsob.200407 | doi-access = free| title = Euglenozoa: Taxonomy, diversity and ecology, symbioses and viruses | year = 2021 | last1 = Kostygov | first1 = Alexei Y. | last2 = Karnkowska | first2 = Anna | last3 = Votýpka | first3 = Jan | last4 = Tashyreva | first4 = Daria | last5 = MacIszewski | first5 = Kacper | last6 = Yurchenko | first6 = Vyacheslav | last7 = Lukeš | first7 = Julius | journal = Open Biology | volume = 11 | issue = 3 | article-number = 200407 }}</ref>
== Nomenclature == The family Euglenaceae is also known by the name Euglenidae. The origin of this dual naming system is because of the history of protists. Euglenids have been treated as both algae and protozoans, which are governed by separate nomenclature codes.<ref name=Patterson>{{cite journal | doi= 10.1111/j.1550-7408.1992.tb01292.x | title= A Perspective on Protistan Nomenclature | year= 1992 | last1= Patterson | first1= David J. | last2= Larsen | first2= Jacob | journal= The Journal of Protozoology | volume= 39 | pages= 125–131 }}</ref> If treated as an alga, it would fall under the International Code of Nomenclature for algae, fungi, and plants (ICN) and its correct name would be Euglenaceae; if treated under the International Code of Zoological Nomenclature (ICZN) it is called Euglenidae.<ref name=Kostygov_2021/> Euglenids such as these are considered to be ambiregnal protists due to their parallel naming systems.<ref name=Patterson/>
== Morphology == Euglenaceae show the most morphological diversity within the class Euglenophyceae.<ref>{{cite journal | doi=10.1111/jeu.12235 | title=Chloroplast Genome Evolution in the Euglenaceae | year=2015 | last1=Bennett | first1=Matthew S. | last2=Triemer | first2=Richard E. | journal=Journal of Eukaryotic Microbiology | volume=62 | issue=6 | pages=773–785 | pmid=25976746 | s2cid=6208110 }}</ref> They are mostly single-celled organisms, except for the genus ''Colacium''. They are free-living or sometimes inhabiting the digestive tracts of animals.<ref name="Kostygov_2021"/> Two genera, ''Strombomonas'' and ''Trachelomonas'' produce outer shells called loricae.<ref name=Kim/>
As with other euglenids, cells in the Euglenaceae are surrounded by a series of proteinaceous strips called the pellicle; the pellicle can stretch in most genera, allowing the cell to contract, creating a type of movement called metaboly. The genus ''Monomorphina'' is rigid or slightly metabolic.<ref name="Kostygov_2021"/> Chloroplasts are present in most species, except for a few species that have lost them.<ref name="Kostygov_2021"/> Chloroplasts are diverse in this family, with the size, shape, number, and presence of pyrenoids being important identifying characteristics.<ref name="Kostygov_2021"/>
== Phylogeny == In its current circumscription, Euglenaceae is monophyletic.<ref name=Kim>{{cite journal | doi=10.1111/j.1529-8817.2010.00910.x | title=Multigene Analyses of Photosynthetic Euglenoids and New Family, Phacaceae (Euglenales) | year=2010 | last1=Kim | first1=Jong Im | last2=Shin | first2=Woongghi | last3=Triemer | first3=Richard E. | journal=Journal of Phycology | volume=46 | issue=6 | pages=1278–1287 | s2cid=86347770 }}</ref> Its sister family is Phacaceae, which contains several genera (''Lepocinclis'', ''Phacus'', and ''Discoplastis'') formerly included within Euglenaceae.<ref name=Kim/> Two phylogenies are shown below.
===Kim et al. (2010)=== In this phylogeny, most ''Euglena'' species are sister to a clade consisting of ''Euglenaria'' and ''Euglena archaeoplastidiata''.<ref name=Kim/> {{Clade|label1=Euglenales|1= {{Clade |label1=Euglenaceae|1= {{Clade |1={{Clade |1={{Clade |1={{Clade |1=''Euglena pro parte'' |2={{Clade |1=''Euglenaria'' |2=''Euglena archaeoplastidiata'' }} }} |2={{Clade |1=''Cryptoglena'' |2=''Monomorphina'' }} }} |2={{Clade |1={{Clade |1=''Strombomonas'' |2=''Trachelomonas'' }} |2={{Clade |1=''Colacium'' |2=''Euglena velata'' }} }} }} |2=''Euglenaformis'' }} |2=Phacaceae (outgroup) }} }}
===Bicudo & Menezes (2016)=== This phylogeny places ''Euglena'' as sister to all other genera in Euglenaceae except for the genus ''Euglenaformis''.<ref>{{cite journal | doi=10.3389/fevo.2016.00017 | doi-access=free | title=Phylogeny and Classification of Euglenophyceae: A Brief Review | year=2016 | last1=Bicudo | first1=Carlos E. de M. | last2=Menezes | first2=Mariângela | journal=Frontiers in Ecology and Evolution | volume=4 }}</ref> {{Clade|label1=Euglenales |1={{clade|label1=Euglenaceae |1={{clade |1={{clade |1=''Euglena pro parte'' |2={{clade |1={{clade |1={{clade |1={{clade |1=''Cryptoglena'' |2=''Monomorphina'' }} |2=''Euglenaria'' }} |2=''Euglena archaeoplastidiata'' }} |2={{clade |1={{clade |1=''Strombomonas'' |2=''Trachelomonas'' }} |2=''Colacium'' }} }} }} |2=''Euglenaformis'' }} |2=Phacaceae (outgroup) }} }}
== References == {{Reflist}}
{{Discoba}} {{Taxonbar|from=Q2132226}} {{Authority control}}
Category:Euglenozoa Category:Euglenozoa families