Locomotor performances of Sea Bass (Dicentrarchus labrax):
Can they be used to predict
success in the field?
The focus of this work is to discover physiological
characteristics that are predictive of sea bass success in the
wild. The method is to establish links between individual variance
in several different types of locomotor performance, ability to
increase oxygen consumption in support of exercise (metabolic
scope) and survival/growth in a mesocosm setting. Scientists often
measure locomotor capacities as an indicator of animal health
or fitness, yet, the relationships between locomotor capacity,
natural selection, and physiology are poorly known for fishes.
The work has taken place in Dr. Guy Claireaux's lab at the Centre
de Recherche en Écologie Marine et Aquaculture (CREMA),
in L'Houmeau, France. The lab is carved out of an abandoned abbey;
the fish holding room is the old chapel; pretty cool, huh?
CNRS-IFREMER Centre de Recherche en Écologie Marine et Aquaculture (CREMA) lab at L'Houmeau, France
There are many reasons that we know little about the ecological relevance of locomotor performance in fishes. Not the least among these are the technical challenges faced when measuring locomotor capacities in aquatic species and problems associated with recapturing marked fish. Along with various key colleagues throughout the years (Dale Webber, Shannon Reidy and Jeff Klupt have been key) I've developed a unique computer driven, laser light/ photocell beam timing technique that redresses some of the problems associated with measuring burst locomotion in large number of fishes. This apparatus has already been used to reproducibly measure sprint velocity of fishes in several different studies. See:
Nelson, J.A. and G. Claireaux. 2005. Inter-individual variance of sprint swimming performance, swimming metabolism and endurance in a cohort of European sea bass (Dicentrarchus labrax). The Transactions of the American Fisheries Society.134 (5) 1274-1284.
Nelson, J.A., P. S. Gotwalt , D.W. Webber and S. Reidy. 2002. Beyond Ucrit: Matching swimming performance tests to the physiological ecology of the animal, including a fish "drag strip". Comparative Biochemistry & Physiology. 133/2 pp 289-302
Martinez, M., Guderley, H., Nelson, J.A., Webber, D., Dutil,
J.D., 2002. Once a fast cod, always a fast cod: maintenance of
performance hierarchies despite changing food availability in
cod (Gadus morhua). in press. Physiological and Biochemical
Zoology. 75 : 90-100.
Reidy, S., S.R. Kerr and J. A. Nelson. 2000. Aerobic and anaerobic swimming performance of individual Atlantic cod. Journal of Experimental Biology. 203: 347-357.
for examples of the sprint chamber in action.
Fish being chased in the sprint chamber at
(CREMA) lab at L'Houmeau, France
This international collaboration will hopefully lead to a more comprehensive understanding of how locomotor abilities and metabolic capacities of fish relate to success in the field.
Close up of a sea
bass breaking the laser beams as it traverses the sprint chamber
This will allow the investigators to also establish the relationship
between traditional measures of fast-start performance and other
tests of locomotor performance. Endurance performance, metabolic
rate and cardiovascular performance will also be assessed during
swim tests in a swim tunnel respirometer. Altogether, these experiments
will clarify the role of locomotor capacity in determining animal
success in the field and help partition that success between anaerobic
and aerobic capabilities. The results of this work will hopefully
improve the use of physiological considerations in making management
and aquaculture decisions concerning sea bass, an emerging food
fish in Europe.
