Trachelomonas armata var. longa

(Deflandre, 1926)

Most likely ID: n.a.


Synonym: n.a.


Sampling location: Simmelried


Phylogenetic tree: Trachelomonas armata var. longa



  • body ellipsoid, anterior end narrower, poles sometimes weakly flattened
  • length 41–43 µm (without spines)
  • anterior fourth covered with short, conical spines
  • posterior end with long, curved spines
  • porus without collar, annular thickened with short spines
  • flagellum twice body length
  • one eyespot
  • chloroplasts disc-shaped, without pyrenoid
  • small paramylon grains in cytoplasm
Trachelomonas armata var. longa

So far I have only found Trachelomonas aramata var. longa exclusively in the Simmelried. It is one of the many described varieties of the parent form Trachelomonas armata. However, Trachelomonas armata var. longa differs from this parent form by the slender shape of the lorica and above all by the short, conical spines, which are arranged in the anterior fourth (s. fig. 1 a). The parent form Trachelomonas armata is naked except for the ring of long, curved spines at the posterior end.


Very similar to Trachelomonas armata var. longa is the variety Trachelomonas armata var. Steinii. The only difference is the shape of the lorica, which in Trachelomonas armata var. Steinii corresponds to the parent form and is broader and shorter.


All specimens of Trachelomonas armata var. longa that I examined had a very constant length of 41–43 µm (without spines), which corresponds exactly to Deflandre’s data.


Fig. 1 a-c: Trachelomonas armata var. longa. L = 42 µm (without spines). Three focal planes of a freely swimming specimen. Note the short, conical spines in the anterior fourth (AS). The long, posterior spines (PS) are arranged in a ring. F = flagellum. Obj. 60 X.


Fig. 2 a-c: Trachelomonas armata var. longa. L = 41 µm (without spines). Three focal planes of a second, freely swimming specimen. Obj. 60 X.


Fig. 3 a-b: Trachelomonas armata var. longa. L = 41 µm (without spines). Two focal planes of a young specimen with a transparent lorica. Obj. 60 X.