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Navicula lanceolata (Agardh) Ehrenberg(1838)

Infusorienthierchen: 185


valve view brightfield

valve view brightfield



live brightfield

Description
Valves linear-lanceolate to lanceolate, with very slightly protracted, bluntly rounded apices. Striae radiate at the centre, becoming convergent at the apices, with a broadly rounded to squarish central area.

CharacterState 
If elliptic or elongate, length 28-70 m 
If elliptic or elongate, width (8)-9-12 m 
If striae resolvable, density 10-13 /10m 
Shape in valve view Elliptical or elongated True
If elliptic or elongate, transapical symmetry Isopolar True
If elliptic or elongate, apical symmetry Isobilateral True
Raphe Present True
If raphe, position Midline of valve face True
If raphe, fibulae Absent True

Habit

CharacterState 
Colonies Solitary cells True
Attachment Not attached (floating or freely motile) True
Motile?Yes 

True Rarely True Unknown
Only by Misinterpretation

Synonyms

  • Frustulia lanceolata Agardh * 1827. Flora oder Botanische Zeitung: 626

* basionym

Taxonomic Comment
Prior to the publication of Krammer & Lange-Bertalot (1986) this diatom was often identified as Navicula viridula Ktz. (following Hustedt 1930). Lange-Bertalot (1980) discussed the taxonomy of this species.

Water quality indicators:

 SVComments
Nutrients   
TDI (UK) 52.0 Optimum occurs between 0.35 and 1 mg l-1 filtrable P
TI (Austria) 3.54.0 Poly ? hypertrophic
Other Indices   
IPS (France) 41.0 Tolerant of mild pollution
Saprobic Index (Austria) 2.32.3 Tolerant of moderate to heavy organic pollution
Saprobicity (Netherlands) 3  α-mesosaprobous
Other Information   
pH 4  Alkaliphilous (mainly occurring at pH > 7)
Salinity - NL 3  Brackish fresh

Comments to: Diatom Key Development Team