Resuspended filament

Description :

This is a typical filament of Aulacoseira (formerly Melosira) granulata (Bacillariophyta, Centrales)that was resuspended from the sediments not long before sampling. Its linking spines are of different lengths, possibly indicative of the filament having been broken at this place. In contrast, spines of equal length as in the other photo of this species are indicative of active growth. The chloroplasts here are partly compacted and do not fill the entire cell volume, indicative of the origin of this particular filament from the sediments. The other photo of this species shows actively growing, planktonic cells with chloroplasts filling the entire cell. This specimen was sampled from the shore of the lake in June 2006.