Caenorhabditis elegans swimming at low Reynolds number

Supplementary material from the paper "Material properties of Caenorhabditis elegans swimming at low Reynolds number," by Josue Sznitman, Prashant K. Purohit, Predrag Krajacic, Todd Lamitina, Paulo E. Arratia, ArXiv, Submitted on 9 Nov 2009 [http://arxiv.org/abs/0911.1731].

Abstract: Undulatory locomotion, as seen in the nematode \emph{Caenorhabditis elegans}, is a common swimming gait of organisms in the low Reynolds number regime, where viscous forces are dominant. While the nematode's motility is expected to be a strong function of its material properties, measurements remain scarce. Here, the swimming behavior of \emph{C.} \emph{elegans} are investigated in experiments and in a simple model. Experiments reveal that nematodes swim in a periodic fashion and generate traveling waves which decay from head to tail. The model is able to capture the experiments' main features and is used to estimate the nematode's Young's modulus $E$ and tissue viscosity $\eta$. For wild-type \emph{C. elegans}, we find $E\approx 3.77$ kPa and $\eta \approx-860$ Pa$\cdot$s; values of $\eta$ for live \emph{C. elegans} are negative because the tissue is generating rather than dissipating energy. Results show that material properties are sensitive to changes in muscle functional properties, and are useful quantitative tools with which to more accurately describe new and existing muscle mutants.
To appear in Biophysical Journal

Category:

Science & Technology

Tags:

• animal locomotion
• biology
• worm
• swimming
• fluid mechanics
• physics

[gespilk]

How does the creature decide to turn left or right. Is it randomness in the level of firing of it neurons or is it some property of the environment affecting its sensory neurons.