Editing Cryptomonad (section)

{{short description|Group of algae and colorless flagellates}}
{{redirect|Cryptophyte||Cryptophyte (disambiguation)}}
{{Automatic taxobox
| name = Cryptomonads
| image = Rhodomonas_salina_CCMP_322.jpg
| image_caption =  ''Rhodomonas salina''
| taxon = Cryptomonada
| authority = [[Thomas Cavalier-Smith|Cavalier-Smith]], 2004 stat. nov. 2015<ref name="Cavalier-Smith 2018">{{cite journal|doi=10.1007/S00709-017-1147-3 |title=Kingdom Chromista and its eight phyla: A new synthesis emphasising periplastid protein targeting, cytoskeletal and periplastid evolution, and ancient divergences |date=2018 |last1=Cavalier-Smith |first1=Thomas |journal=Protoplasma |volume=255 |pages=297–357 |pmid=28875267 |pmc=5756292 }}</ref>
|display_parents=6
| subdivision_ranks = Classes & orders
| subdivision_ref = <ref name="Cavalier-Smith 2018"/>
| subdivision = 
* [[Goniomonadea]]
** [[Hemiarmida]]
** [[Goniomonadida]]
* [[Cryptophyceae]]
** [[Cryptomonadales]]
** [[Tetragonidiales]]
}}

The '''cryptomonads''' (or '''cryptophytes''')<ref>Barnes, Richard Stephen Kent (2001). ''The Invertebrates: A Synthesis''. Wiley-Blackwell. p. 41. {{ISBN|978-0-632-04761-1}}.</ref> are a [[Class (biology)|superclass]] of [[algae]],<ref name="pmid18397952">{{cite journal |author=Khan H, Archibald JM |title=Lateral transfer of introns in the cryptophyte plastid genome |journal=Nucleic Acids Res. |volume=36 |issue=9 |pages=3043–53 |date=May 2008 |pmid=18397952 |pmc=2396441 |doi=10.1093/nar/gkn095 |url=}}</ref> most of which have [[chloroplast|plastids]]. They are traditionally considered a [[Division (taxonomy)|division]] of [[algae]] among [[phycologist]]s, under the name of '''Cryptophyta'''.<ref>{{cite journal|doi=10.1016/j.protis.2004.12.003 |title=The Katablepharids are a Distant Sister Group of the Cryptophyta: A Proposal for Katablepharidophyta Divisio Nova/Kathablepharida Phylum Novum Based on SSU rDNA and Beta-Tubulin Phylogeny |date=2005 |last1=Okamoto |first1=N. |last2=Inouye |first2=I. |journal=Protist |volume=156 |issue=2 |pages=163–179 |pmid=16171184 }}</ref> They are common in freshwater, and also occur in marine and brackish habitats. Each cell is around [[1 E-5 m|10–50 μm]] in size and flattened in shape, with an anterior groove or pocket. At the edge of the pocket there are typically two slightly unequal [[flagellum|flagella]]. Some may exhibit [[mixotrophy]].<ref name="urlCryptophyta - the cryptomonads">{{cite web|url=http://www.life.umd.edu/labs/delwiche/PSlife/lectures/Cryptophyta.html/wwwtax.cgi?mode=Info&id=412159&lvl=1|title=Cryptophyta - the cryptomonads|access-date=2009-06-02|url-status=dead|archive-url=https://web.archive.org/web/20110610151135/http://www.life.umd.edu/labs/delwiche/PSlife/lectures/Cryptophyta.html/wwwtax.cgi?mode=Info&id=412159&lvl=1|archive-date=2011-06-10}}</ref> They are classified as superclass '''Cryptomonada''', which is divided into two classes: heterotrophic [[Goniomonadea]] and phototrophic [[Cryptophyceae]]. The two groups are united under three shared morphological characteristics: presence of a [[periplast]], [[ejectisomes]] with secondary scroll, and mitochondrial [[cristae]] with flat tubules.<ref>{{cite book | last = Cavalier-Smith| first = Thomas| title  =Organelles, Genomes, and Eukaryote Phylogeny | year = 2004| pages = 87–88}}</ref> Genetic studies as early as 1994 also supported the hypothesis that ''Goniomonas'' was sister to Cryptophyceae.<ref>{{Citation |last=McFadden, Gilson, & Hill |year=1994 |title=Goniomonas: rRNA sequences indicate that this phagotrophic flagellate is a close relative of the host component of cryptomonads |journal=European Journal of Phycology |volume=29 |issue=1 |pages=29–32 |doi=10.1080/09670269400650451}}</ref> A study in 2018 found strong evidence that the common ancestor of Cryptomonada was an autotrophic protist.<ref>{{Citation |last=Cenci |year=2018 |title=Nuclear genome sequence of the plastid-lacking cryptomonad Goniomonas avonlea provides insights into the evolution of secondary plastids |journal=BMC Biology  |volume=16 |issue=1 |pages=137 |doi=10.1186/s12915-018-0593-5|pmid=30482201 |pmc=6260743 |doi-access=free }}</ref>