Loxophyllum uninucleatum was described by Kahl from a body of water with 2.0–2.5 % salinity. However, I was able to clearly detect this species in the Simmelried in December 2024. The species was very common in the samples from floating plants. However, I had never been able to detect Loxophyllum uninucleatum before.

Loxophyllum uninucleatum was described by Kahl in 1928. In 1978 Foissner described a Litonotus species with extrusomes in the posterior end as Litonotus uninucleatus. In 1989 Loxophyllum uninucleatum was then found and described by Weibo & Wilbert. Based on the characteristics, the authors decided to transfer the species to the genus Litonotus as Litonotus uninucleatus, but recognized that the name Litonotus uninucleatus had already been given by Foissner and recommended a new name without making a proposal. Finally, Foissner et al. (1992) identified the species found by Weibo & Wilbert as Litonotus alpestris. A new, valid name has therefore never been given to Loxophyllum uninucleatum, which means that the name first given by Kahl (Loxophyllum uninucleatum) remains valid.

The specimens of my population correspond exactly to the description of Kahl. The specimens were 85-103 µm long. The rod-shaped extrusomes were exclusively localized in the oral cleft. The posterior end was slightly pointed in all specimens and the contractile vacuole was clearly subterminal. Kahl mentions that Loxophyllum uninucleatum feeds exclusively on Euglena. I can confirm this because I found large quantities of paramylon grains in the cytoplasm of all specimens (s. fig. 3 b).

Contrary to Kahl’s description, I was able to detect a thin layer of mucilage about 1 µm thick in Loxophyllum uninucleatum (s. fig. 4). It was clearly recognizable in all specimens. At the highest magnification, the layer appears “rough”, which indicates that small scales are embedded in the layer below the resolution of the light microscope.