Allometric Scaling of Maximal Enzyme Activities in the Axial Musculature of Striped Bass,Morone saxatilis(Walbaum)

Abstract

It had been suggested that the activity of anaerobic enzymes in the white muscle of fish increases exponentially with body size to meet the increasing hydrodynamic costs of burst swimming. We tested whether this relationship holds across a very large size range of striped bass, spanning a nearly 3,000-fold range in body mass. We examined the scaling of marker enzymes of anaerobic (lactate dehydrogenase and pyruvate kinase) and aerobic (citrate synthase and malate dehydrogenase) metabolism in the red and white locomotor muscles. In white muscle, we found positive scaling of anaerobic enzymes only in smaller fishes. Positive scaling of anaerobic enzymes was not found among the samples that included fishes >1,000 g despite having a sufficiently large sample size to detect such scaling. The absence of positive scaling in the white muscles of large bass suggests that they are unable to generate sufficient power to sustain relative burst swimming performance. Enzymes from aerobic pathways had activities that were mass independent in both red and white muscle. Red and white muscles were metabolically distinct except among the smallest fishes. Among young of the year, the anaerobic capacity of red muscle approached that of white muscle and also showed positive scaling. This unusual pattern suggests that red muscle might augment white muscle during burst swimming and add to the total power generated by these small fish. Maximizing burst swimming performance may be critical for small fishes vulnerable to predation but unimportant for large fishes.

Seasonal acclimatisation of muscle metabolic enzymes in a reptile(Alligator mississippiensis)

“…It may be that scaling of oxygen consumption is caused by oxygen transport constraints rather than by mass-specific changes in oxygen demand (Goolish, 1991;Bejan, 1997). The lack of constant scaling of metabolic enzyme activity is not uncommon among ectotherms (Baldwin et al, 1995;Norton et al, 2000), as scaling of enzyme activity may be a function of several biotic factors such as developmental stage (Garenc et al, 1999) and size-specific demands for locomotory performance (Somero and Childress, 1980). Hence, more detailed experimental studies are needed to determine the nature of the scaling relationship, or lack thereof, of metabolic enzyme activity in alligators, particularly considering the relatively narrow body mass range of our study animals in winter.…”

Control of muscle bioenergetic gene expression: implications for allometric scaling relationships of glycolytic and oxidative enzymes

“…Fish models also provide an opportunity to examine intraspecific variation in animals of similar geometry. In contrast to the situation in mammals, mitochondrial enzymes of most fish are independent of body mass (Somero and Childress, 1990;Burness et al, 1999;Norton et al, 2000). As in mammals, glycolytic enzymes show positive scaling, with exponents ranging from 0.15 (barred sand bass; Yang and Somero, 1996) to 0.4 (rainbow trout; Somero and Childress, 1990;Burness et al, 1999).…”

Beyond body size: muscle biochemistry and body shape explain ontogenetic variation of anti-predatory behaviour in the lizard Salvator merianae (Squamata: Teiidae)

“…The results for enzyme activity in the hindlimb muscle differ from those obtained for the jaw muscle: juvenile tegus have a hindlimb muscle that is proportionally more glycolytic than that of adults, a trend that contributes for understanding why recently-hatched tegus rely on running away from a predator regardless of thermal conditions (de Barros et al, 2010). Although energetic demands would favour during growth a reduction in the levels of aerobic metabolism coupled with increased anaerobic rates (for discussions on scaling-effects, see Somero and Childress, 1980;Childress and Somero, 1990;Norton et al, 2000;and Moyes and Genge, 2010 for a review), in juveniles locomotion may face increased selection pressures triggered by predation rates, summed to their developmental demands (Kirkton et al, 2011). In that sense, phenotypes that enhance escaping, such as hindlimb muscles that are comparatively more glycolytic, may compensate for restrictions imposed by environmental conditions involving low temperatures.…”

“…Biochemical properties of hindlimb and head muscles were assessed based on maximum activity of two metabolic enzymes: lactate dehydrogenase (LDH) was used as an indicator of oxygenindependent pathways, whereas citrate synthase (CS) represented the muscle aerobic metabolism (Eme et al, 2009;Fields et al, 2008;Kirkton et al, 2011;Kohlsdorf et al, 2004;Norton et al, 2000;Rosa et al, 2009;Seibel et al, 1998;de Souza et al, 2004;Vetter and Lynn, 1997). Enzyme activities were measured using a Beckman DU-70 spectrophotometer under saturating and noninhibitory substrate conditions, following de Souza et al (2004), as further detailed.…”