Coleps elongatus

(Ehrenberg, 1830) Kahl, 1930

Most likely ID: n.a.


Synonym: n.a.


Sampling location: Purren pond


Phylogenetic tree: Coleps elongatus



  • length 65–80 µm
  • cell slender barrel-shaped to almost cylindrical
  • two caudal cilia
  • anterior end with two teeth
  • uniform ciliation
  • 14–17 longitudinal rows of plates
  • “windows” in armour pretzel-shaped
  • one spherical macronucleus
  • apical mouth opening with basket of pharyngeal trichites
Coleps elongatus

So far I have been able to detect Coleps elongatus only in the Purren pond. Possibly I have overlooked the Coleps species in the specimens from my other localities, because a safe assignment is possible only on the basis of the 2 caudal cilia and the form and arrangement of the “windows” in the armour. However, the species is conspicuous in its slender shape even at low magnification. The “windows” of Coleps elongatus are pretzel-shaped, like in Coleps hirtus. However, Coleps elongatus has 5 “windows” in a row per half cell (s. fig. 3), while Coleps hirtus has only 4 “windows” per half cell.


Fig. 1 a-d: Coleps elongatus. L = 65 µm. A freely swimming specimen. Note the two caudal cilia (CC). Obj. 40 X.


Fig. 2 a-c: Coleps elongatus. L = 65 µm. The slightly squashed specimen shown in fig. 1 a-d. Obj. 100 X.


Fig. 3: Coleps elongatus. A strongly squashed specimen for visualisation of the pretzel-shaped “windows”.  Per half cell each 5 “windows” are arranged in a row (1–5). Obj. 100 X.