View source for Biology:Synurid

{{Short description|Group of algae}}
{{Automatic taxobox
| taxon = Synurales
| authority = Andersen, 1987
| name = Synurids
| image = Synura.jpg
| image_caption = A colony of ''Synura'' sp.
| subdivision_ranks = Genera<ref name="Developmentsinthesilica"/>
| subdivision =
*''[[Biology:Mallomonas|Mallomonas]]''
*''[[Biology:Synura|Synura]]''
*''Tessellaria''
}}

The '''synurids''' (order '''Synurales''') are a small group of [[Biology:Heterokont|heterokont]] algae, found mostly in freshwater environments, characterized by cells covered in [[Chemistry:Silica|silica]] scales.<ref name="MorphoSynurapetersenii"/>

==Characteristics==
[[File:Synura_petersenii.png|thumb|left|upright|alt=High magnification SEM image of a single Synura cell: It is covered with about 50 delicate, oval scales.|A single cell of the freshwater algae species ''Synura petersenii'', false color image created using [[Physics:Scanning electron microscope|SEM]]]]
They are covered in silicate scales and spines.  In ''Synura'', these are formed on the surface of the [[Biology:Chloroplast|chloroplast]]s,<ref>{{citation |author=Barry S.C. Leadbeater |year=1990 |title=Ultrastructure and assembly of the scale case in ''Synura'' (Synurophyceae Andersen) |journal=British Phycological Journal |volume=25 |issue=2 |pages=117–132 |doi=10.1080/00071619000650111|doi-access=free }}</ref> two of which are usually present, but sometimes only one divided into two lobes is seen.  The cells have two heterokont [[Biology:Flagellum|flagella]], inserted parallel to one another at the anterior, whose ultrastructure is a distinguishing characteristic of the group.  Both asexual and [[Biology:Isogamy|isogamous]] sexual reproduction occur.

==Genera==
Two major genera are included here, divided into species mainly based on the structure of the scales.

* ''[[Biology:Mallomonas|Mallomonas]]'' species are free-living individual cells, usually 50–100 μm in length.  They have ornate scales and generally long spines.
* ''[[Biology:Synura|Synura]]'' species occur as spherical colonies, with the cells oriented so that the flagella point outwards, each usually around 30 μm in length.  The colonies are globular, rather than hollow, and spines are short if at all present.

Both are common [[Earth:Plankton|plankton]] in lakes and ponds. In high concentrations, they dye the water yellow, and produce a distinctive odour.

To reproduce the parent cell splits into two daughter cells which get half of the parent cells scales. The new cells can regrow the scales and grow back into their original form.

==History==
The genus ''Synura'' was proposed in 1834 by the German microscopist [[Biography:Christian Gottfried Ehrenberg|Christian Gottfried Ehrenberg]] (1795–1876).<ref>See:
*  {{cite journal |last1=Ehrenberg |title=Dritter Beitrag zur Erkenntniss grosser Organisation in der Richtung des kleinsten Raumes |journal=Abhandlungen der Königlichen Akademie der Wissenschaften zu Berlin [Treatises of the Royal Academy of Sciences in Berlin] |date=1833 |pages=145–336 |trans-title=Third contribution to [our] knowledge of greater organization in the direction of the smallest realm |language=de |url=https://www.biodiversitylibrary.org/item/93805#page/181/mode/1up }}  [https://www.biodiversitylibrary.org/item/93805#page/317/mode/1up From p. 281:]  Ehrenberg created a new family, ''Volvocina'', ''" ... wozu ich die vier neuen Gattungen ''Chlamidomonas'', ''Syncrypta'', ''Synura'', und ''Uroglena'' stelle."''  ( ... into which I place the four new genera ''Chlamidomonas'', ''Syncrypta'', ''Synura'', and ''Uroglena''.)  [Note:  According to p. 145, Ehrenberg's paper was first presented in 1832, revised somewhat, and published in 1834.]
*  See also:  [http://www.algaebase.org/search/genus/detail/?genus_id=43807 AlgaeBase:  ''Synura'' Ehrenberg, 1834]</ref>

The synurids were originally included among the golden algae in the order Ochromonadales as the family Mallomonadaceae or as the family Synuraceae
.  They were formally defined as a separate group by Andersen in 1987, who placed them in their own class '''Synurophyceae''', based on an earlier approach of more narrowly defining major lineages of chrysophyte algae by British phycologist David Hibberd.<ref>{{cite journal|doi=10.1111/j.1095-8339.1976.tb01352.x|title=The ultrastructure and taxonomy of the Chrysophyceae and Prymnesiophyceae (Haptophyceae): A survey with some new observations on the ultrastructure of the Chrysophyceae|year=1976|last1=Hibberd|first1=D. J.|journal=Botanical Journal of the Linnean Society|volume=72|issue=2|pages=55–80}}</ref><ref>{{cite journal|doi=10.1016/0303-2647(79)90025-X|title=The structure and phylogenetic significance of the flagellar transition region in the chlorophyll c-containing algae|year=1979|last1=Hibberd|first1=David J.|journal=Biosystems|volume=11|issue=4|pages=243–261|pmid=396946}}</ref>

The [[Biology:Chrysophyceae|Chrysophyceae]] and Synurophyceae are currently recognized as closely related taxa within the [[Biology:Stramenopile|Stramenopile]]s.<ref name="pmid19282238">{{cite journal |vauthors=Grant J, Tekle YI, Anderson OR, Patterson DJ, Katz LA |title=Multigene Evidence for the Placement of a Heterotrophic Amoeboid Lineage Leukarachnion sp. among Photosynthetic Stramenopiles |journal=Protist |volume= 160|issue= 3|pages= 376–85 |date=March 2009 |pmid=19282238 |doi=10.1016/j.protis.2009.01.001 }}</ref><ref name="PNG">{{cite journal |author=W. Vyverman |author2=G. Cronberg |title=Scale bearing chrysophytes from Papua New Guinea |journal=Nordic Journal of Botany |volume= 13|issue= 1|pages= 111–20 |date=March 1993 |doi=10.1111/j.1756-1051.1993.tb00022.x }}</ref> Present classifications include the synurids as an order (Synurales) within [[Biology:Chrysophyceae|Chrysophyceae]].<ref name="MorphoSynurapetersenii"/><ref name="8phyla"/>

==References==
{{Reflist|refs=

<ref name="MorphoSynurapetersenii">{{cite journal|title=Morphological delineation and distribution patterns of four newly described species within the Synura petersenii species complex (Chrysophyceae, Stramenopiles)|vauthors=Škaloud P, Škaloudová M, Procházková A, Němcová Y|doi=10.1080/09670262.2014.905710|date=2014|volume=49|issue=2|journal=European Journal of Phycology|pages=213–229|doi-access=free}}</ref>

<ref name="8phyla">{{cite journal|title=Kingdom Chromista and its eight phyla: a new synthesis emphasising periplastid protein targeting, cytoskeletal and periplastid evolution, and ancient divergences|first1=Thomas|last1=Cavalier-Smith|date=2017|journal=Protoplasma|pages=297–357|volume=255|issue=1 |doi=10.1007/s00709-017-1147-3|pmid=28875267 |pmc=5756292 }}</ref>

<ref name="Developmentsinthesilica">{{cite journal|title=Developments in the taxonomy of silica-scaled chrysophytes – from morphological and ultrastructural to molecular approaches|first1=Pavel|last1=Škaloud|first2=Jørgen|last2=Kristiansen|first3=Magda|last3=Škaloudová|journal=Nordic Journal of Botany|volume=31|issue=4|date=July 2013|publication-date=August 2013|pages=385–402|doi=10.1111/j.1756-1051.2013.00119.x}}</ref>

}}

==External links==

{{Heterokont}}
{{Taxonbar|from=Q948998|from2=Q21286588}}

[[Category:Ochrophyta]]



{{Sourceattribution|Synurid}}