''Fragilaria'' is a genus of

freshwater Fresh water or freshwater is any naturally occurring liquid or frozen water containing low concentrations of dissolved salts and other total dissolved solids. Although the term specifically excludes seawater and brackish water, it does include ...

and saltwater

diatom A diatom (Neo-Latin ''diatoma''), "a cutting through, a severance", from el, διάτομος, diátomos, "cut in half, divided equally" from el, διατέμνω, diatémno, "to cut in twain". is any member of a large group comprising sev ...

s. It is usually a colonial diatom, forming filaments of cells mechanically joined by protrusions on the face and in the center of their valves. The individual diatoms appear swollen in their centers where they are joined to the colonial ribbon. the genus grows as both plankton and benthic species, free living in colonies or epiphytic. Some species are bloom forming diatoms in eutrophic lakes. The type species is '' Fragilaria pectinalis'' Lyngbye from designating a lectotype from ''Conferva pectinalis'' O.F.Müller. The taxonomy of the genus is still uncertain. ''Fragilaria'' has been the dominant genus of diatoms in

Lake Mývatn A lake is an area filled with water, localized in a basin, surrounded by land, and distinct from any river or other outlet that serves to feed or drain the lake. Lakes lie on land and are not part of the ocean, although, like the much larger ...

in Iceland for at least 1200 years. The genus currently accounts for around 93% of all diatoms in the lake.

Description

The ''Fragilaria'' have a pseudoraphe, rather than a true longitudinal groove in their valves. The valves are symmetrical with transverse striae.

Some species

*'' F. acidoclinata'' *'' F. aconicinnum'' *'' F. acus'' *'' F. acutirhombica'' *'' F. acutiuscula'' *'' F. alpestris'' *'' F. amphicephaloides'' *'' F. annulata'' *'' F. aquaplus'' *'' F. arctica'' *'' F. austriaca'' *'' F. barbararum'' *'' F. barbatula'' *'' F. bidens'' *'' F. bipunctata'' *'' F. birostris'' *'' F. brevistriata'' *'' F. bronkei'' *'' F. californica'' *'' F. canariensis'' *'' F. cassubica'' *'' F. constricta'' *'' F. construens'' *'' F. crassirhombica'' *'' F. crotonensis'' *'' F. demerarae'' *'' F. denticulata'' *'' F. dibolos'' *'' F. dzonoticola'' *'' F. ehrenbergii'' *'' F. eichornii'' *'' F. excissa'' *'' F. famelica'' *'' F. flexura'' *'' F. foliolum'' *'' F. fragilarioides'' *'' F. fremontii'' *'' F. gedanensis'' *'' F. germanii'' *'' F. glebula'' *'' F. gnathastoma'' *'' F. goulardii'' *'' F. gracilis'' *'' F. gracillicima'' *'' F. gracillima'' *'' F. grandis'' *'' F. grunowii'' *'' F. hantzschiana'' *'' F. henryi'' *'' F. hirosakiensis'' *'' F. hoelii'' *'' F. husvikensis'' *'' F. hyalina'' *'' F. improbula'' *'' F. incisa'' *'' F. incognita'' *'' F. interstincta'' *'' F. islandica'' *'' F. kriegeriana'' *'' F. labei'' *'' F. lacus-baikalensis'' *'' F. lacus-baikali'' *'' F. lenzii'' *'' F. leptarthra'' *'' F. longiceps'' *'' F. longifusiformis'' *'' F. magocsyi'' *'' F. marina'' *'' F. mazamaensis'' *'' F. micra'' *'' F. microvaucheriae'' *'' F. miniscula'' *'' F. nanana'' *'' F. nanoides'' *'' F. nevadensis'' *'' F. northumbrica'' *'' F. oblongata'' *'' F. opacolineata'' *'' F. pacifica'' *'' F. pantocsekii'' *'' F. paradoxa'' *'' F. pararumpens'' *'' F. parva'' *'' F. patagonica'' *'' F. pelta'' *'' F. pennsylvanica'' *'' F. perdelicatissima'' *'' F. perminuta'' *'' F. pseudoconstruens'' *'' F. pseudolaevissima'' *'' F. ptagonica'' *'' F. punctata'' *'' F. punctiformis'' *'' F. quebecensis'' *'' F. radians'' *'' F. recapitellata'' *'' F. rhodana'' *'' F. riesgoviensis'' *'' F. robusta'' *'' F. rolandschmidtii'' *'' F. rostrata'' *'' F. rotundissima'' *'' F. sandellii'' *'' F. santaremensis'' *'' F. saxoplanctonica'' *'' F. schulzi'' *'' F. schulzii'' *'' F. similis'' *'' F. sinuata'' *'' F. smithiana'' *'' F. socia'' *'' F. sopotensis'' *'' F. spinarum'' *'' F. striatula'' *'' F. submicroscopica'' *'' F. suboldenburgiana'' *'' F. tenera'' *'' F. tenuicollis'' *'' F. toxoneides'' *'' F. turgens'' *'' F. uliginosa'' *'' F. ulna'' *'' F. ulnus'' *'' F. utermoehlii'' *'' F. vaucheriae'' *'' F. viereckiana'' *'' F. virescens'' *'' F. vitrea'' *'' F. zeilleri''

References

External links

* {{Taxonbar, from=Q1440428 Diatom genera Fragilariophyceae