''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 incl ...

and

saltwater Saline water (more commonly known as salt water) is water that contains a high concentration of dissolved salts (mainly sodium chloride). On the United States Geological Survey (USGS) salinity scale, saline water is saltier than brackish water, ...

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 se ...

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 In biology, a type is a particular specimen (or in some cases a group of specimens) of an organism to which the scientific name of that organism is formally attached. In other words, a type is an example that serves to anchor or centralizes the ...

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 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