Beobachtung von Diatomeen

Malformations in Cymatopleura solea

Cymatopleura solea will serve as a further example of malformations that occur in older cultures. Diatoms of this species were isolated from Lake Ebnisee (48░55'25.5"N 9░36'32.8"E) on 25 March 2017 and kept in clonal culture. About every other week diatoms of a parent culture were inoculated into a subsequent culture. The video at the top shows (30x time lapse) a view into such a culture taken on 16 May 2017. At that time, the diatoms still had an almost uniform length of about 160 Ám.

In the following months a gradual reduction of the diatoms was observed. Malformations occurred in larger numbers from August 2018. The following video is taken on 7 November 2018:

(20x time lapse when using 10x objective; 10x time lapse at higher magnifications)

The length of the diatoms was typically in the range of 55 Ám to 75 Ám. The arched deformed diatoms, however, had a length of only about 45 Ám (distance from apex to apex). The following picture gives an impression of the valves of such diatoms:

Valves of malformed diatoms

The left valve shows only a slight asymmetry with respect to the apical axis.

Thomas Harbich