Observations on

Nuclearia Cienkowsky 1865

Most likely ID: Nuclearia simplex

Synonyms: n. a.

EOL Phylogenetic tree: Nuclearia

Defecation in Nuclearia

Fig. 1: Defecation in a Nuclearia cell. a Cell with large defecation vacuole. b The vacuole has migrated to the edge of the cell. c The vacuole has opened to the outside. d and e The indigestible material is being discharged. f End of the defecation process. Scale bar indicates 25 µm. Sample from a tropical freshwater aquarium.

Fig. 1 shows a Nuclearia cell which has trapped a large piece of indigestible material in a vacuole. Its shininess in polarized light indicated its birefringent property. This and the fibrous structure leads to the conclusion that it is cellulose. The series of images shows how the piece of cellulose was excreted. Unlike ciliates, for example, amoeboids have no special areas prepared for defecation openings, no cytoproct. Fig. 1 f gives the impression that the large piece of waste affected the cell somewhat during the excretion process. In the genus Nuclearia, however, the formation of such cell appendagesis not uncommon.