title: Suction-based propulsion as a basis for efficient animal swimming.
abstract: A central and long-standing tenet in the conceptualization of animal swimming is the idea that propulsive thrust is generated by pushing the surrounding water rearward. Inherent in this perspective is the assumption that locomotion involves the generation of locally elevated pressures in the fluid to achieve the expected downstream push of the surrounding water mass. Here we show that rather than pushing against the surrounding fluid, efficient swimming animals primarily pull themselves through the water via suction. This distinction is manifested in dominant low-pressure regions generated in the fluid surrounding the animal body, which are observed by using particle image velocimetry and a pressure calculation algorithm applied to freely swimming lampreys and jellyfish. These results suggest a rethinking of the evolutionary adaptations observed in swimming animals as well as the mechanistic basis for bio-inspired and biomimetic engineered vehicles.
authors.affiliation: Department of Integrative Biology, University of South Florida, Tampa, Florida 33620, USA.|Eugene Bell Center, Marine Biological Laboratory, Woods Hole, Massachusetts 02543, USA.
authors.forename: Brad J
authors.initials: BJ
authors.lastname: Gemmell
authors.affiliation: Eugene Bell Center, Marine Biological Laboratory, Woods Hole, Massachusetts 02543, USA.|Marine Biology and Environmental Sciences, Roger Williams University, Bristol, Rhode Island 02809, USA.
authors.forename: Sean P
authors.initials: SP
authors.lastname: Colin
authors.affiliation: Eugene Bell Center, Marine Biological Laboratory, Woods Hole, Massachusetts 02543, USA.|Biology Department, Providence College, Providence, Rhode Island 02918, USA.
authors.forename: John H
authors.initials: JH
authors.lastname: Costello
authors.affiliation: School of Engineering, Stanford University, Stanford, California 94305, USA.
authors.forename: John O
authors.initials: JO
authors.lastname: Dabiri
mesh_terms: D000465:Algorithms; D000818:Animals; D005075:Biological Evolution; D001696:Biomechanical Phenomena; D048428:Petromyzon / Q000502:physiology*; D011312:Pressure; D012212:Rheology; D037401:Scyphozoa / Q000502:physiology*; D013550:Swimming / Q000502:physiology*