Nephrocytium limneticum (G. M. Smith, 1933)

Most likely ID: n.a.


Synonym: Gloeocystopsis limnetica


Sampling location: Hagstaffel pond


Phylogenetic tree: Nephrocytium limneticum



  • coenobia of 4–8–16 cells in mucilage envelope
  • daughter colonies 20–50 µm in diameter
  • daughter cells remain united within gelatinized cell wall of mother cell
  • cells 10–15 µm long, kidney-shaped, slightly curved with rounded apices
  • one pyrenoid
  • one parietal chloroplast
  • planctonic lifestyle
Nephrocytium limneticum

I find Nephrocytium limneticum very rarely in plankton samples, always with several years between them. Nephrocytium can be confused with Kirchneriella, whose cells are also kidney-shaped or crescent-shaped. However, the colonies of Nephrocytium are covered by a distinct and thick layer of mucus, which is absent in Kirchneriella. In addition, the daughter colonies of Nephrocytium remain united for a long time in the swollen and gelatinized cell wall of the mother cell (s. fig. 2 a).


Fig. 1: Nephrocytium limneticum. L = 156 (of coenobium). A coenobium of 8 colonies with 16 cells each within the gelatinized cell wall of the mother cell. Obj. 40 X.


Fig. 2 a-b: Nephrocytium limneticum. L = 10–12 µm (of the cells). A slightly squashed (a) and a strongly squashed (b) coenobium of 4 colonies with 4 cells each within the remains of the mother cell (RMC). Each colony is in a thick mucilage envelope (ME). Nu = nucleus, PY = pyrenoid. Obj. 100 X.