Beobachtung von Diatomeen

Malformations in Nitzschia sp.

Malformations and their causes were discussed in connection with Surirella biseriata.
I observed very pronounced abnormalities in a Nitzschia species. At the start of cultivation in February 2016, the average cell length was 146 Ám. Because of the short lifetime of a culture of only two to three weeks, I inoculated a new culture every week. The generation time was very short, so that the bottom of the petri dish was already densely populated after just one week. The following video (25x time lapse) shows a look into a culture shortly after the beginning of cultivation:

After 18 months of cultivation there was much less motility and the cultures did not thrive well. The following picture (PlasDIC) of a culture shows significant abnormalities:

malformed Nitzschia

The mean length of the diatoms reached only 38 Ám. It was thus only 26 % of the original length.

Malformation exemplary On the left there are three diatoms in larger magnification. Shortly after these pictures were taken the culture was given up. As in the case of Surirella biseriata, I suspect that the cause of the malformations is the very small size. Unfortunately, as in nearly all our cultures, there was no sexual reproduction.

Thomas Harbich