Skip to main content

Intra-school positional preference and reduced tail beat frequency in trailing positions in schooling roach under experimental conditions

Buy Article:

$43.00 plus tax (Refund Policy)

Using three different swimming velocities and a school size of eight roach Rutilus rutilus, individual intra-school position and tail beat frequency were examined in a flume tank. Tail beat frequency was determined in defined leading and trailing positions. Individual roach showed consistent intra-school positional preferences which implied a sustained positional pattern where certain individuals took up front positions whereas other individuals swam in the rear part of the school. The positional preferences could not be attributed to inter-individual differences of the eight roach in terms of total length, mass or condition factor. At the tested swimming velocities of 2, 3 and 4 LT s−1, roach in trailing positions swam with tail beat frequencies reduced by 7·3, 11·9 and 11·6%, respectively, compared to roach in leading positions. These results suggested that roach situated in trailing positions experienced energetic savings due to hydrodynamic interactions at a wide range of swimming velocities. This may be important during migrations or when a school of roach is holding its position against the current in a lotic habitat. The observed sustained positional pattern combined with a hydrodynamic advantage in trailing positions would indicate that these energetic savings might not be evenly shared among schoolmates of roach. A positive correlation between swimming velocity and stride length was found. The present study, however, does not support any conclusions concerning these findings.
No References
No Citations
No Supplementary Data
No Article Media
No Metrics

Keywords: Rutilus rutilus; energy saving; hydrodynamics; intra-school positioning; stride length; vortex street

Document Type: Regular Paper

Affiliations: 1: Department of Animal Behaviour, University of Copenhagen, Tagensvej 16, 2200 Copenhagen N, Denmark and 2: Marine Biological Laboratory, University of Copenhagen, Strandpromenaden 5, 3000 Helsingør, Denmark

Publication date: 01 April 2003

  • Access Key
  • Free content
  • Partial Free content
  • New content
  • Open access content
  • Partial Open access content
  • Subscribed content
  • Partial Subscribed content
  • Free trial content
Cookie Policy
X
Cookie Policy
Ingenta Connect website makes use of cookies so as to keep track of data that you have filled in. I am Happy with this Find out more