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

Roche, D.G., Taylor, M.K., Binning, S.A., Johansen, J.L., Domenici, P., and Steffensen, J.F. (2014) Unsteady flow affects swimming energetics in a labriform fish (Cymatogaster aggregata). Journal of Experimental Biology, 217. pp. 414-422.

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Abstract

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, during station holding. Using intermittent-flow respirometry, we measured critical swimming speed (U-crit), oxygen consumption rates (MO2) and pectoral fin use in steady flow versus unsteady flows with either low-[0.5 body lengths (BL) s(-1)] or high-amplitude (1.0 BL s(-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.

Item ID: 32958
Item Type: Article (Research - C1)
ISSN: 1477-9145
Keywords: complex flow, critical swimming speed, fin-beat frequency, pectoral fin swimming, oxygen consumption rate, respirometry
Funders: Friday Harbour Laboratories, Australian National University (ANU), Natural Sciences and Engineering Research Council of Canada, Fisheries Society, Danish Natural Sciences Research Council
Date Deposited: 30 Apr 2014 09:29
FoR Codes: 06 BIOLOGICAL SCIENCES > 0602 Ecology > 060205 Marine and Estuarine Ecology (incl Marine Ichthyology) @ 30%
06 BIOLOGICAL SCIENCES > 0606 Physiology > 060601 Animal Physiology - Biophysics @ 40%
06 BIOLOGICAL SCIENCES > 0602 Ecology > 060201 Behavioural Ecology @ 30%
SEO Codes: 96 ENVIRONMENT > 9608 Flora, Fauna and Biodiversity > 960808 Marine Flora, Fauna and Biodiversity @ 100%
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