I find the macroscopically visible thalli of Chaetophoropsis elegans very frequently in the Simmelried. The thalli are either free-floating, lying loosely on the layer of mud, or attached to other aquatic plants and pieces of wood. Most of the time, I only find thalli that are a few millimeters in size, more or less spherical in shape.

The green alga Chaetophoropsis elegans was first described by Roth in 1806 as Chaetophora elegans. In 2019, it was renamed Chaetophoropsis elegans by B.W. Liu et al. based on genetic and morphological studies.

The thalli of Chaetophoropsis elegans consist of radially arranged filaments, which branch repeatedly towards the end. This results in a dense arrangement of branched filaments on the outside (s. figs. 2 and 3). The ends of these filaments taper to a terminal cell, which is bluntly pointed (s. fig. 3). However, some filaments do not end in terminal cells but instead form a seta (s. figs. 4 and 5). This is formed by repeated cell division, with the chloroplast of the cell being increasingly degraded after each division (s. fig. 5). In the distal cells of the seta, the protoplasts eventually die off as well, leaving behind empty, colorless cells that form the seta.

The thalli of Chaetophoropsis elegans are often colonized by unicellular algae, ciliates, and rotifers. Therefore, it is always worthwhile to examine the thalli more closely. In addition to ponds and bogs, Chaetophoropsis elegans is also native to freshwater aquariums, where it colonizes aquatic plants, wood, or glass as light green balls or cushions. It is undesirable among aquarists but difficult to remove.