QUICK SEARCH:   [advanced] Author: Keyword(s):
Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents

First published online July 26, 2004
Journal of Experimental Biology 207, 2979-2990 (2004)
Published by The Company of Biologists 2004
doi: 10.1242/jeb.01142

This Article Figures Only Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Martínez, M. Articles by Guderley, H. Search for Related Content PubMed PubMed Citation Articles by Martínez, M. Articles by Guderley, H.

Does condition of Atlantic cod (Gadus morhua) have a greater impact upon swimming performance at U_crit or sprint speeds?

M. Martínez¹, M. Bédard¹, J.-D. Dutil² and H. Guderley^1,*

¹ Université Laval, Département de Biologie, Québec, G1K 7P4, Canada
² Ministère des Pêches et des Océans, Institut Maurice-Lamontagne, 850 Route de la Mer, C.P. 1000, Mont-Joli, Québec, G5H 3Z4, Canada

^* Author for correspondence (e-mail: helga.guderley{at}bio.ulaval.ca)

Accepted 14 June 2004

To compare the sensitivity of sprint and critical (U_crit) swimming speeds to the condition of Atlantic cod (Gadus morhua) and to identify the best anatomic, behavioural and biochemical correlates of these types of swimming, we established two groups of cod that were fed or starved for 12 weeks. We evaluated sprint swimming and U_crit performance as well as the speed at which repeated burst-coast movements began in the U_crit test before measuring the metabolic capacities of red and white muscle sampled caudally, centrally and rostrally and the anatomic characteristics of the cod. White muscle lactate was measured directly after the U_crit test. As expected, the twofold difference in Fulton's condition factor (0.5±0.04 for starved and 1.0±0.1 for fed cod) was accompanied by large differences in the anatomic and biochemical parameters measured. Despite the relative sparing of muscle aerobic capacity during starvation and despite the greater use of oxidative fibres during U_crit compared with sprint swimming, these types of swimming differed by much the same extent between starved and fed cod. In the U_crit tests, white muscle lactate levels and lactate accumulation per burst-coast movement were considerably higher in fed than starved cod, suggesting more intensive use of fast muscle fibres in cod in good condition. Multiple regression analysis indicated strong correlations between U_crit, the speed at which regular burst-coasting began and the activity of pyruvate dehydrogenase (PDH) in red muscle (both caudal and central positions). PDH activity may limit the rate of oxidative ATP production by red muscle. The activity of cytochrome c oxidase in rostral white muscle was the strongest correlate of sprint swimming, suggesting that aerobic preparation of white muscle facilitates rapid contraction. The correlation between U_crit and sprint swimming was weak, perhaps due to inter-individual differences in sensitivity during sprint tests.

Key words: white muscle, red muscle, condition, U_crit swimming, sprint swimming, aerobic metabolism, anaerobic metabolism, Atlantic cod, Gadus morhua.

This article has been cited by other articles:

				N Derome and L Bernatchez The Transcriptomics of Ecological Convergence between 2 Limnetic Coregonine Fishes (Salmonidae) Mol. Biol. Evol., December 1, 2006; 23(12): 2370 - 2378. [Abstract] [Full Text] [PDF]