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Unsteady flow affects swimming energetics in a labriform fish (Cymatogaster aggregata)

Authors :
Dominique G. Roche
Paolo Domenici
Mark K. Taylor
John F. Steffensen
Jacob L. Johansen
Sandra A. Binning
Source :
Journal of Experimental Biology.
Publication Year :
2013
Publisher :
The Company of Biologists, 2013.

Abstract

Summary Unsteady water flows are common in nature, yet the swimming performance of fishes is typically evaluated at constant, steady speeds in the laboratory. We examined how cyclic changes in water flow velocity affect the swimming performance and energetics of a labriform swimmer, the shiner surfperch, Cymatogaster aggregata. Using intermittent-flow respirometry, we measured critical swimming speed (Ucrit), oxygen consumption rate (ṀO2) and pectoral fin use in steady flow versus unsteady flows with either low (0.5 body lengths per second; BLs-1) or high amplitude (1.0 BLs-1) velocity fluctuations, with a 5 s period. Individuals in low amplitude unsteady flow performed as well as fish in steady flow. However, swimming costs in high amplitude unsteady flow were on average 25.3 % higher than in steady flow and 14.2% higher than estimated values obtained from simulations based on the non-linear relationship between swimming speed and oxygen consumption rate in steady flow. Time-averaged pectoral fin use (fin beat frequency measured over 300 s) was similar among treatments. However, measures of instantaneous fin use (fin beat period) and body movement in high amplitude unsteady flow indicate that individuals with greater variation in the duration of their fin beats were better at holding station and consumed less oxygen than fish with low variation in fin beat period. These results suggest that the costs of swimming in unsteady flows are context dependent in labriform swimmers, and may be influenced by individual differences in the ability of fishes to adjust their fin beats to the flow environment.

Details

ISSN :
14779145 and 00220949
Database :
OpenAIRE
Journal :
Journal of Experimental Biology
Accession number :
edsair.doi.dedup.....72abfcb44b384c41bca8b08e85d200a4