TY - ABST

T1 - Fish positions relative to neighbours modulate the hydrodynamic advantages of schooling

AU - Steffensen, John Fleng

PY - 2012

Y1 - 2012

N2 - Soc for experimental Biol Annual Meeting - Salzburg 2012Stefano Marras (Istituto di Scienza e Tecnologie dell'lnformazione'A. Faedo', CNR, Italy), Shaun S Killen (University of Glasgow,Scotland, UK), David J. McKenzie (CNRS, France), John F. Steffensen(University of Copenhagen, Denmark) and Paolo Domenici (CNR, Italy)Schooling behaviour is a widespread phenomenon shared by a largenumber of fish species. One of the most common benefits of swimmingin a school is the hydrodynamic and energetic advantage obtained by itsmembers. Fish occupying non-frontal positions can benefit from the flowgenerated by the caudal movement of fish swimming in the front.While previous work has demonstrated that trailing fish show a lowertail beat frequency (TBF) than leading fish , the extent to which schoolingprovides hydrodynamic advantages compared to swimming alone has notbeen quantified. We quantified this by filming individual grey mullet Lizaaurata when swimming alone (n=20) and the same fish when swimmingin a school (n=20; eight fish per school, with one focal fish in each school)at three swimming speeds in a swim-tunnel. TBF was measured in focalfish swimming to the side of a neighbour, using a range of distances alongthe direction of locomotion, spanning one body length (BL) in the front(+1 BL) and behind (-1 BL) a neighbouring fish.We found a significant reduction in the mean TBF of fish whenswimming in a school versus solitary fish . Furthermore, the TBF of thefocal fish decreased linearly between the two extreme positions (from+1 BL to -1 BL), with the lowest values at -1 BL.This work provides direct evidence that schooling provideshydrodynamic advantages compared to solitary swimming and thatsmall changes in the position of an individual fish relative to neighboursmodulates these advantages.Email addressforcorrespondence: stefano.marras@iamc.cnr.it

AB - Soc for experimental Biol Annual Meeting - Salzburg 2012Stefano Marras (Istituto di Scienza e Tecnologie dell'lnformazione'A. Faedo', CNR, Italy), Shaun S Killen (University of Glasgow,Scotland, UK), David J. McKenzie (CNRS, France), John F. Steffensen(University of Copenhagen, Denmark) and Paolo Domenici (CNR, Italy)Schooling behaviour is a widespread phenomenon shared by a largenumber of fish species. One of the most common benefits of swimmingin a school is the hydrodynamic and energetic advantage obtained by itsmembers. Fish occupying non-frontal positions can benefit from the flowgenerated by the caudal movement of fish swimming in the front.While previous work has demonstrated that trailing fish show a lowertail beat frequency (TBF) than leading fish , the extent to which schoolingprovides hydrodynamic advantages compared to swimming alone has notbeen quantified. We quantified this by filming individual grey mullet Lizaaurata when swimming alone (n=20) and the same fish when swimmingin a school (n=20; eight fish per school, with one focal fish in each school)at three swimming speeds in a swim-tunnel. TBF was measured in focalfish swimming to the side of a neighbour, using a range of distances alongthe direction of locomotion, spanning one body length (BL) in the front(+1 BL) and behind (-1 BL) a neighbouring fish.We found a significant reduction in the mean TBF of fish whenswimming in a school versus solitary fish . Furthermore, the TBF of thefocal fish decreased linearly between the two extreme positions (from+1 BL to -1 BL), with the lowest values at -1 BL.This work provides direct evidence that schooling provideshydrodynamic advantages compared to solitary swimming and thatsmall changes in the position of an individual fish relative to neighboursmodulates these advantages.Email addressforcorrespondence: stefano.marras@iamc.cnr.it

M3 - Conference abstract for conference

ER -