Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published December 15, 2016 | Supplemental Material + Published
Journal Article Open

How the bending kinematics of swimming lampreys build negative pressure fields for suction thrust


Swimming animals commonly bend their bodies to generate thrust. For undulating animals such as eels and lampreys, their bodies bend in the form of waves that travel from head to tail. These kinematics accelerate the flow of adjacent fluids, which alters the pressure field in a manner that generates thrust. We used a comparative approach to evaluate the cause-and-effect relationships in this process by quantifying the hydrodynamic effects of body kinematics at the body–fluid interface of the lamprey, Petromyzon marinus, during steady-state swimming. We compared the kinematics and hydrodynamics of healthy control lampreys to lampreys whose spinal cord had been transected mid-body, resulting in passive kinematics along the posterior half of their body. Using high-speed particle image velocimetry (PIV) and a method for quantifying pressure fields, we detail how the active bending kinematics of the control lampreys were crucial for setting up strong negative pressure fields (relative to ambient fields) that generated high-thrust regions at the bends as they traveled all along the body. The passive kinematics of the transected lamprey were only able to generate significant thrust at the tail, relying on positive pressure fields. These different pressure and thrust scenarios are due to differences in how active versus passive body waves generated and controlled vorticity. This demonstrates why it is more effective for undulating lampreys to pull, rather than push, themselves through the fluid.

Additional Information

© 2016. Published by The Company of Biologists Ltd http://www.biologists.com/user-licence-1-1/ Received June 14, 2016. Accepted September 30, 2016. Published online December 14, 2016. We thank Eric Tytell and Kelsey Lucas for their insightful comments and discussion on the manuscript. This work was funded by a National Science Foundation (NSF) CBET grant awarded to S.P.C., J.H.C., B.J.G. and J.O.D. (award numbers 1510929, 1511996), by the Marine Biological Laboratory (J.R.M.) and by the Roger Williams University Foundation to Promote Teaching and Scholarship. Author contributions: B.J.G., J.H.C., J.R.M. and S.P.C. conceived of and designed the study; J.R.M. and S.M.F. carried out transection operations; B.J.G. carried out experimental work; J.O.D. and S.P.C. carried out data analysis; S.P.C. wrote the manuscript; B.J.G., J.H.C., J.O.D., J.R.M. and S.P.C. revised the manuscript. All authors gave final approval for publication. The authors declare no competing or financial interests.

Attached Files

Published - 3884.full.pdf

Supplemental Material - JEB144642supp.pdf


Files (4.5 MB)
Name Size Download all
4.4 MB Preview Download
158.4 kB Preview Download

Additional details

August 19, 2023
October 20, 2023