So far, I have only found Treubaria triappendiculata once in August 2023 in the plankton of the pond of the waste disposal company Constance. I have not been able to find this species in any of my other sampling sites.

Most of the specimens I examined had 7 or 8 spiny appendages. Therefore it can only be Treubaria triappendiculata, because all other described Treubaria species have only 4 appendages. However, the distinction between the species seems to be in flux, because Treubaria euryacantha, which was described with 4 appendages, is now synonymous with Treubaria triappendiculata. The number of spiny appendages therefore seems to be variable. I have also noticed that the appendages can become detached very easily, which is why often specimens with an odd number of appendages can be found.

The cells in my population were all asymmetrically roundish and had a diameter of more than 15 µm. I could only recognize one pyrenoid at a time, and older cells were often opaque.