Euchlanis triquetra Ehrenberg, 1838

Most likely ID: n.a.

 

Synonym: n.a.

 

Sampling location: Simmelried, Pond St. Ulrich (Austria) 

 

Phylogenetic tree: Euchlanis triquetra

 

Diagnosis: 

  • body broad elliptical, dorsal plate tri-radiate
  • dorsal plate with a posterior V-shaped notch
  • oval ventral plate smaller than dorsal plate
  • length of lorica upt to 710, width up to 540 µm
  • slender toes up to 150 long, parallel sided with a short tip
  • stomach usually green, yellow or brown
  • a pair of setae at the distal end of first foot segment
  • one eyespot with lens
Euchlanis-triquetra
Euchlanis triquetra

Euchlanis triquetra is usually found in bodies of water with many aquatic plants, where this species likes to stay. Its diet consists mainly of algae and flagellates.

 

Euchlanis triquetra is best identified in freely swimming specimens. It is important to recognize the keel of the dorsal plate of the lorica. The dorsal plate is also wing-like in shape and often has a V-shaped notch at the posterior end. A ventral plate is absent. The lorica can grow up to 710 µm long. In specimens from my population, the loricae were 300–350 µm long.

 

Euchlanis triquetra can easily be confused with Euchlanis incisa. This species also has a dorsal keel. But Euchlanis incisa has a clearly visible oval ventral plate, and its lorica is only up to 270 µm long.

 

More images and information on Euchlanis triquetra: Michael Plewka-Freshwater life-Euchlanis triquetra

Euchlanis-triquetra

Fig. 1 a-b: Euchlanis triquetra. L = 315 µm (of lorica). Two focal planes of a slightly squashed specimen from ventral. Note the posterior V-shaped notch (PN) of the dorsal plate. Obj. 20 X.

Euchlanis-triquetra

Fig. 2: Euchlanis triquetra. L = 325 µm (of lorica). A freely swimming specimen in brightfield illumination. Obj. 20 X.

Euchlanis-triquetra

Fig. 3: Euchlanis triquetra. Apical view of a freely swimming specimen. Note the prominent dorsal keel (DK). Obj. 10 X.

Euchlanis-triquetra

Fig. 4: Euchlanis triquetra. L = 334 µm (of lorica). A slightly squashed specimen from ventral. Obj. 40 X.

Euchlanis-triquetra

Fig. 5 a-b: Euchlanis triquetra. L = 340 µm (of lorica). Two focal planes of the body. Note the two apical palps (PA) and the eyespot with lens (ES). GG = gastric gland, ST = stomach, Vit = vitellarium. Obj. 40 X.

Euchlanis-triquetra

Fig. 6 a-b: Euchlanis triquetra. The foot (FO) and the toes (TO) with a length of 118 µm in detail. Obj. 40 X.

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