Trichocerca dixon-nuttalli

Jennings, 1903

Most likely ID: n.a.

 

Synonym: n.a.

 

Sampling location: Simmelried

 

Phylogenetic tree: Trichocerca dixon-nuttalli

 

Diagnosis: 

  • body almost cylindrical, slightly curved
  • anterior end folded with close head
  • length 90–122 µm
  • one apical palp organ
  • two almost straight, parallel toes of different length
  • two secondary, short toes (hard to see)
  • gastric glands with irregular shape
  • one cervical eyespot
Trichocerca-dixon-nuttalli
Trichocerca dixon-nuttalli

So far, I have only found Trichocerca dixon-nuttalli in the Simmelried between floating plant masses and in the uppermost mud layer. However, I only find this species very rarely.

 

The main characteristics of Trichocerca dixon-nuttalli are the almost straight toes. These are two closely spaced toes of different lengths. The longer of the two toes has almost body length. The two toes are barely recognizable in freely swimming specimens, but only separate in squashed specimens (s. fig. 3). The two toes are accompanied by two secondary toes, which are considerably shorter and difficult to recognize. Another important feature are the irregularly shaped gastric glands, which have a slightly wavy surface (s. fig. 2 b). In addition, the right lateral antenna of Trichocerca dixon-nuttalli is shifted far posteriorly compared to the left lateral antenna. However, I could not recognize this feature.

 

More images and information on Trichocerca dixon-nuttalli: Michael Plewka-Freshwater life-Trichocerca dixon-nuttalli

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Fig. 1 a-c: Trichocerca dixon-nuttalli. L = 172 µm. Different focal planes of a slightly squashed specimen from left. Obj. 60 X.

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Fig. 2 a-c: Trichocerca dixon-nuttalli. L = 146 µm. An extended (a, b) and contracted (c) second specimen. Note the irregularly shaped gastric glands. BL = bladder, CG = cerebral ganglion, ES = eyespot, ST = stomach, TO = toes. Obj. 100 X.

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Fig. 3: Trichocerca dixon-nuttalli. The two toes (TO 1, TO 2) in a squashed specimen. Obj. 100 X.

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Fig. 4: Trichocerca dixon-nuttalli. The trophi in a strongly squashed specimen. Obj. 100 X.