Wow, great comments on this case! The Old One mentioned that this is a bdelloid rotifer. He comments "In this year of the women, it should be noted that bdelloid rotifers are all female. Able to be successful for millennia while maintaining genetic diversity by taking DNA from other creatures." Fascinating! According to the Encyclopaedia Britannica, "Rotifer, also called wheel animalcule, any of the approximately 2,000 species of microscopic, aquatic invertebrates that constitute the phylum Rotifera. Rotifers are so named because the circular arrangement of moving cilia (tiny hairlike structures) at the front end resembles a rotating wheel."
There is no clinical significance to this finding. Rotifers are found in environmental water sources, so it is likely that the organism entered the specimen through the collection process - possibly from toilet water contaminated with untreated water.
We've seen a rotifer before on this blog - in Case of the Week 304. Check out the photos from the case contributor, Ahrong Kim in South Korea - they're beautiful!