Influences of temperature upon the postexercise physiology of Atlantic salmon(Salmo salar)

Abstract

Atlantic salmon (Salmo salar) were acclimated and exhaustively exercised at 12, 18, or 23°C to determine how temperature influences the magnitude of postexercise physiological disturbances. At each temperature, exercise led to decreased white muscle ATP and phosphocreatine concentrations. Phosphocreatine was rapidly restored within 1 h at each temperature whereas ATP restoration took 1-4 h at 18 and 23°C, but considerably longer at 12°C. Exercise-induced depletions of white muscle glycogen were accompanied by elevations in muscle lactate, which contributed to 0.6 unit decreases in white muscle intracellular pH (pHi) at each temperature. Compared with rates of recovery in warmer water, glycogen resynthesis, lactate catabolism, and pHicorrection were slower at 12°C. White muscle REDOX state estimates suggested that slower postexercise recovery at 12°C was not due to oxygen delivery limitations. Marked postexercise elevations in plasma osmolality and lactate concentration were also observed and in each case correction of the disturbance took longer at 12°C. Paradoxically, significant mortality (30%) was observed only at 23°C. We conclude that while warmer water facilitates postexercise recovery of white muscle metabolic and acid-base status in Atlantic salmon, extremely high temperatures may make them more vulnerable to delayed postexercise mortality.

Rapid Metabolic Recovery Following Vigorous Exercise in Burrow‐Dwelling Larval Sea Lampreys(Petromyzon marinus)

“…In addition, the ratio of glycogen disappearance versus lactate appearance in ammocoetes was not 1 : 2, as reported in adult lampreys and in many salmonids following anaerobic exercise (e.g., Milligan and Wood 1986;Schulte et al 1992;Boutilier et al 1993;Kieffer et al 1994;Wang et al 1994a;Wilkie et al 1997). One must keep in mind, however, that the glycolytic intermediates (e.g., glucose-6-phosphate, fructose-6-phosphate, glycerol-3-phosphate, pyruvate) plus lactate, should be considered when attempting to account for postexercise drops in glycogen concentration, as demonstrated by Pearson et al (1990) in their studies on rainbow trout.…”

“…This slurry was then quickly mixed and centrifuged at 10,000 g for 30 s, and the supernatant was transferred to 1.5-mL centrifuge tubes, which were stored at Ϫ80ЊC. The samples were subsequently analysed for ATP, PCr, creatine, glycogen, lactate, and pyruvate using established enzymatic assays (see Boutilier et al 1993;Wilkie et al 1997 for further details). Whole-body glycogen was determined on neutralized extracts digested in five volumes of 30% KOH and analysed using amyloglucosidase and hexokinase (Hassid and Abraham 1957).…”

Temperature Effects on Recovery of Pacific Cod Following Exhaustive Exercise

“…Differences in recovery rate seen in other studies occurred over wider temperature ranges than those examined in this experiment and included three temperature groups. Wilkie et al (1997) acclimated Atlantic salmon to 12, 18, and 23ºC and Galloway and Kieffer (2003) examined Atlantic salmon at 6, 12, and 18ºC. To effectively demonstrate a temperature effect on recovery, one would need to greatly increase the observation time post-exhaustion.…”

“…In Atlantic salmon (Salmo salar), rates of glycogen synthesis, lactate catabolism, and restoration of pH balance following exhaustive exercise were higher for fish acclimated at warm (18-23ºC) compared to cool temperature (12ºC) (Wilkie et al 1997). However, Kieffer et al (1994) found that rainbow trout (Oncorhynchus mykiss) acclimated to a higher temperature (18ºC) had similar glycogen and lactate recovery times compared to fish acclimated to a lower temperature (5ºC).…”

Water temperature modeling in the Garonne River (France)

“…• C may be considered lethal for this species (Alabaster, 1967;Elliott, 1991;Wilkie et al, 1997). Understanding the thermal regime of watercourses is therefore very important for management of aquatic resources and fisheries.…”