Epicarchesium pectinatum was first described by Zacharias (1897) as Zoothamnium pectinatum. After a re-description by Kahl (1935), the species was renamed Carchesium pecitinatum. However, important features of the species are a tuberculate pellicle and the myonema in the branched stalks are interrupted at the ramification sites. On the basis of these features, Foissner, Berger and Schaumburg (1999) finally placed the species in the genus Epicarchesium.

I have only found Epicarchesium pectinatum once so far, in May 2020. The site was the eutrophic pond of the waste disposal company Constance. The colonies in my samples consisted of up to 20 zooids. I did not find any larger colonies. The first characteristic for identification is the swimming style, because the colonies swim with the stem end first (s. fig. 1).

The stalks of the colonies are branched and contracts spirally. Inside the stalks, the string-like myoneme is clearly recognizable (s. fig. 8). At the ramification sites, however, the myoneme is interrupted and provided with a transverse wall. This transverse wall acts like a predetermined breaking point. The daughter cells formed can easily detach from this point. What remains is a wedge-shaped notch. If several daughter cells detach one after the other, a serrated structure is formed (s. fig. 13), which is very characteristic of Epicarchesium pectinatum.

The pellicle and the edge of the peristome are densely covered with tubercles (s. fig. 6) which vary in size and are arranged in transverse rows. The two contractile vacuoles, which empty into the oral funnel, can only be recognized with certainty in slightly squashed specimens (s. fig. 3 a-b). This may be the reason why they were partly overlooked by earlier authors. The macronucleus lies along the longitudinal axis of the cell and is J-shaped (s. fig. 5). I could not identify the micronucleus. However, it is also not mentioned by earlier authors, which is probably why it is difficult to identify.