In December 2022 I found a 162 µm long gastrotrich in the mud of the Simmelried with features that suggest a classification in the genus Ichthydium. The head is oval and slightly narrowed towards the anterior end (s. figs. 4 a-b and 5). Apically there is an almost rectangular kephalion, which protrudes slightly (s. fig. 5). Most representatives of Ichthydium have a soft cuticle and are completely naked. Only a few species have a delicate longitudinal striation on the dorsal side (e.g. Ichthydium fossae). In my specimen, however, I could clearly recognize scales at high magnification, both on the dorsal and the ventral side (s. figs. 6, 7, 8 and 9). These very delicate scales are lanceolate, with a distal, simple spine (s. fig. 7). The scales are 12–15 µm long. The spines make up about 60% of the scale length. The spines overlap the lanceolate parts of the scales, giving the impression that they are keeled. However, this is not the case. Identical scales are found on the ventral side (s. fig. 9). The toes are very short at about 10 µm and conical in shape (s. fig. 10). At the entrance of the intestine a thickening ring can be recognized, which is typical for the genus Ichthydium (s. 4 b). The pharynx is almost cylindrical, without thickening and about 40 µm long (s. fig. 4 a).

Similar species within the genus Ichthydium are Ichthydium bifaciale and Ichthydium brachykolon. However, Ichthydium bifaciale is completely naked, has no rectangular kephalion and the toes are significantly larger (17–18 µm) while the head of Ichthydium brachykolon is wider than the body and the pharynx is said to show a distinct thickening in the middle, which is not the case in my species. In addition, Ichthydium brachykolon is somewhat smaller (about 130 µm) and the cuticle is also completely naked.

Since no comparable species is described in the literature available to me, it could be a new species that has not yet been described.