Abstract
The habitat of ciliates is widely spread and encompasses the ocean, soil, and digestive tract of mammals. Some ciliates live on surfaces; however, the effect of geometric constraints on their behavior and habitat is still largely a mystery. In this article, we discuss the behavior of swimming ciliates under various geometric constraints. To gain insight, we first calculated the lubrication forces exerted on a cell under various geometric constraints, where the cell was modeled as a squirmer. We then examined the behavior of cells near a free surface, a rigid wall, and in complex geometries. Our results show that cell behavior was strongly dependent on the geometric constraints and swimmer type; for example, some cells became entrapped, whereas others were able to escape. The mechanism underlying the behavior was well represented by the derived lubrication forces, providing a better understanding of cell behavior in natural and industrial environments. In addition, this article provides a brief overview of the field and the outlook for future research in this area.
Highlights
We discussed the effects of geometric constraints on the behavior of swimming ciliates
T. thermophila was entrapped by a free surface, but escaped from a rigid wall
II showed a much stronger escape torque exerted by the rigid wall than by the free surface, indicating that cells can escape from the rigid wall much more than from the free surface
Summary
Ciliated protozoa emerged as an evolutionary group more than 1 × 109 years ago, separating from the eukaryotic line that led to plants and animals before fungi appeared.[1]. They observed clustering of cells, which was again mediated by a wall boundary These former studies emphasize the importance of geometric constraints, the physical mechanism by which ciliates interact with surfaces remains largely a mystery. The mechanism of entrapment has been explained by hydrodynamic and steric effects.[13,14,15,16] Collective swimming of bacteria in confined geometries has been reported;[17,18,19] the results showed that self-organized spatiotemporal patterns occur on scales that are large compared with those of individual cells. The physical mechanism of the rheotaxis has been explained by hydrodynamic and steric effects.[32,33] These previous studies illustrate that geometric constraints have a considerable influence on the behavior and habitat of cells. Some analytical studies on the behaviors of a ciliate near a solid wall have been conducted,[36–38] our understanding has to be strengthened much further
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
