2010/12/21 by Sean Gart, Dominic Vella, Gart, Sean +3
Biochemistry, Genetics and Molecular Biology · Engineering · Physics and Astronomy · #Adhesion, Friction, and Surface Interactions #Biological Physics (physics.bio-ph) #FOS: Physical sciences #Fluid Dynamics (physics.flu-dyn) #Insect and Arachnid Ecology and Behavior #Micro and Nano Robotics #physics.bio-ph #physics.flu-dyn
paper · pdf · doi:10.48550/arxiv.1012.4798
arxiv created 2010/12/21 · openalex publication_date 2010/12/21 · arxiv updated 2010/12/22 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Many organisms live in confined fluidic environments such as the thin liquid layers on the skin of host organisms or in partially- saturated soil. We investigate the collective behaviour of nematodes in a thin liquid layer, which was first observed by Gray and Lissmann, [J. Exp. Biol. 41, 135 (1964)]. We show experimentally that nematodes confined by a thin liquid film come into contact and only separate again after some intervention. We attribute this collective motion to an attractive force between them arising from the surface tension of the layer and show that for nearby nematodes this force is typically stronger than the force that may be exerted by the nematodes' muscles. We believe this to be the first demonstration of the "Cheerios effect" acting on a living organism. However, we find that being grouped together does not significantly alter the body stroke and kinematic performance of the nematode: there are no statistically significant changes of the Strouhal number and the ratio of amplitude to wavelength when aggregated. This result implies that nematodes gain neither a mechanical advantage nor disadvantage by being grouped together; the capillary force merely draws and keeps them together.