{{Short description|Genus of algae}} {{Automatic taxobox | image = Medeiros_et_al_2021_Ankistrodesmus_bibraianus.jpg | image_caption = ''Selenastrum bibraianum'' | taxon = Selenastrum | authority = Reinsch | type_species = ''Selenastrum bibraianum''<br/><small>Reinsch, 1866</small> | subdivision_ranks = Species | subdivision_ref = <ref name=AlgaeBase/> | subdivision = * ''Selenastrum bibraianum'' * ''Selenastrum bifidum'' * ''Selenastrum densum'' * ''Selenastrum rinoi'' * ''Selenastrum subtile'' * ''Selenastrum westii'' | synonyms = }}
'''''Selenastrum''''' is a genus of green algae in the family Selenastraceae.<ref>See the NCBI [https://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&id=39954 webpage on Selenastrum]. Data extracted from the {{cite web | url=https://ftp.ncbi.nih.gov/pub/taxonomy/ | title=NCBI taxonomy resources | publisher=National Center for Biotechnology Information | access-date=2007-03-19}}</ref> It is common in freshwater habitats around the world.<ref name=Shubert2014/> Most species prefer temperate or warm-temperate waters.<ref name=AlgaeBase>{{AlgaeBase genus | Selenastrum | id=43450 | access-date=2024-12-27 }}</ref>
The genus was circumscribed by the German phycologist Paul Friedrich Reinsch in 1866.<ref name=AlgaeBase/> The name ''Selenastrum'' comes from the Greek roots ''selene'', meaning "moon", and ''astron'', meaning "star".<ref name=CarolinaLucidKey>{{cite web|url=https://fmp.conncoll.edu/silicasecchidisk/LucidKeys3.5/Keys_v3.5/Carolina35_Key/Media/Html/Selenastrum_Main.html|title=Selenastrum|first1= Hannah|last1= Shayler|first2=Peter A.|last2=Siver|work=Carolina Lucid Key to Freshwater Algae|publisher=Connecticut College | date=2004 |access-date=2023-12-28 }}</ref>
==Description== ''Selenastrum'' forms colonies of cells, numbering four, eight, 16, or 32. Cells are strongly curved and crescent-shaped, with pointed ends; the cells are attached to each other on their convex sides. Each cell contains a single parietal chloroplast.<ref name=Shubert2014>{{cite book |editor-first1=John D.|editor-last1=Wehr|editor-first2=Robert G.|editor-last2=Sheath|editor-first3=J. Patrick|editor-last3=Kociolek |date= 2014 |edition=2 |title= Freshwater Algae of North America: Ecology and Classification |last1= Shubert|first1=Elliot| last2=Gärtner |first2=Georg |chapter= Chapter 7. Nonmotile Coccoid and Colonial Green Algae |url= |location= |publisher= Elsevier Inc. |page= |isbn=978-0-12-385876-4 }}</ref>
Like other members of the family, ''Selenastrum'' reproduces asexually, by forming autospores.<ref name=Fawley>{{cite journal | doi=10.1111/j.1529-8817.2006.00169.x | title=Evaluating the Morphospecies Concept in the Selenastraceae (Chlorophyceae, Chlorophyta) | year=2006 | last1=Fawley | first1=Marvin W. | last2=Dean | first2=Michelle L. | last3=Dimmer | first3=Stephanie K. | last4=Fawley | first4=Karen P. | journal=Journal of Phycology | volume=42 | issue=1 | pages=142–154 | bibcode=2006JPcgy..42..142F | s2cid=53318143 }}</ref> Zoospores and sexual reproduction have not been observed in this genus.<ref name=AlgaeBase/>
==Taxonomy== ''Selenastrum'' has had an unstable taxonomic history.<ref name=Bicudo_and_Menezes2006>{{cite book | title= Gêneros de Algas de Águas Continentais do Brasil: chave para identificação e descrições | edition=2 | year=2006 | first1=Carlos E. M. |last1=Bicudo | first2=Mariângela | last2= Menezes | publisher= RiMa Editora | pages=508 | isbn= 857656064X }}</ref> ''Selenastrum'' is distinguished from the similar and related genus ''Ankistrodesmus'' by the curvature of the cells; ''Selenastrum'' has more strongly curved cells. The two genera have sometimes been considered congeneric,<ref name=Krienitz>{{cite journal | doi=10.1046/j.1529-8817.2001.01004.x | title=Traditional generic concepts versus 18S rRNA gene phylogeny in the green algal family Selenastraceae (Chlorophyceae, Chlorophyta) | year=2001 | last1=Krienitz | first1=Lothar | last2=Ustinova | first2=Iana | last3=Friedl | first3=Thomas | last4=Huss | first4=Volker A. R. | journal=Journal of Phycology | volume=37 | issue=5 | pages=852–865 | s2cid=84625065 | doi-access=free | bibcode=2001JPcgy..37..852K }}</ref> but molecular phylogenetic studies have shown them to be found in different clades.<ref>{{cite journal|doi= 10.1007/s00343-024-4082-0|title= ''Selenastrum densum'' sp. nov., a new member of the genus Selenastrum (Selenastraceae, Chlorophyceae, Chlorophyta)|date= 2024|last1= Liu|first1= Xudong|last2= Ma|first2= Na|last3= Feng|first3= Jia|last4= Lü|first4= Junping|last5= Liu|first5= Qi|last6= Nan|first6= Fangru|last7= Liu|first7= Yang|last8= Pan|first8= Liang|last9= Xie|first9= Shulian|journal= Journal of Oceanology and Limnology|volume= 43|issue= 3|pages= 967–983|bibcode= 2025JOL....43..967L}}</ref>
In 2016, the genera ''Messastrum'' and ''Curvastrum'' were created, differing from ''Selenastrum'' mainly in their 18S rDNA and ''rbcL'' gene sequences. ''Curvastrum'' additionally differs from ''Selenastrum'' in its colony size, forming solitary cells or colonies of up to four cells. Both genera are monotypic, containing the species ''Messastrum gracile'' (formerly ''Selenastrum gracile'') and ''Curvastrum pantanale'', respectively.<ref name=Garcia>{{cite journal | doi= 10.5507/fot.2016.010 | title= Selenastraceae (Sphaeropleales, Chlorophyceae): ''rbcL'', 18S rDNA and ITS-2 secondary structure enlightens traditional taxonomy, with description of two new genera, ''Messastrum'' gen. nov. and ''Curvastrum'' gen. nov. | year= 2017 | last1= Garcia Da Silva | first1= Thaís | last2= Bock | first2= Christina | last3= Sant'Anna | first3= Célia Leite | last4= Bagatini | first4= Inessa Lacativa | last5= Wodniok | first5= Sabina | last6= Vieira | first6= Armando Augusto Henriques | journal= Fottea | volume= 17 | issue= 1 | pages= 1–19 | doi-access= free | bibcode= 2017Fotte..17....1G }}</ref>
==References== {{Reflist|1}}
{{Taxonbar|from=Q7447852}} {{Authority control}}
Category:Sphaeropleales genera Category:Sphaeropleales Category:Freshwater algae