Assertion: ciliate | /r/HasProperty | spirostomum
Facets:
Source sentences:
text: Some freshwater protozoans, especially the ciliates Spirostomum, Loxodes, and Plagiopyla, avoid unpleasant conditions, especially lack of oxygen, by abandoning their bottom-dwelling way of life and swimming upward to position themselves at a level where some oxygen is available but where they are not in direct competition with planktonic species.