Cylindrotheca closterium

Click on image to view photo information.
  
Taxonomic Group:Diatom
Trophic Status:Autotrophic
Size Range:25-100 μm long (Cupp 1943); 2.5-8 μm wide x 30-400 μm long (Horner 2002, Tomas 1997)
Key Characteristics:Central part of cell fusiforme with long tapering flexible ends that may curve in the same or opposite directions; valves weakly silicified; two chloroplasts in the broad center of the cell, never in the ends; numerous narrow girdle bands and a simple canal raphe
Confused With:Nitzschia longissima, which is more coarsely silicified and has differences in the valve structure that are very difficult to see; it is entirely likely that over the years we have counted some Nitzschia longissima cells as C. closterium, as accurate identifications depend on acid-cleaned material; see p. 293 in Tomas 1997 for details on structural differences between the two
Toxin:None known