Nucleic acids and enzymes in Atlantic cod (Gadus morhua) differing in condition and growth rate trajectories

Abstract

Atlantic cod (Gadus morhua) were exposed to one of four feeding regimes, 16 weeks of food deprivation (U) or satiation feeding (F) or two 8-week periods of food deprivation followed by satiation feeding (UF) or vice versa (FU), to determine whether relationships between nucleic acids or enzymes and growth rates result from a general enhancement of individual condition or are a direct result of enhanced growth rates. Final condition factor (K) differed between treatments, but did not differ between the mixed treatments after either 8 weeks of negative growth (FU) or 8 weeks of positive growth (UF). Intestinal cytochrome c oxidase activity matched the expected short-term growth rates, not only in fed and unfed fish but also in cod exposed to the mixed treatments (FU and UF). White muscle lactate dehydrogenase activity reflected growth rates, but initial levels were not reached within 8 weeks in FU cod. The liver glutamate pyruvate transaminase : DNA ratio reflected differences in K, but not differences in recent growth rates. Myofibrillar proteins decreased in unfed cod, while sarcoplasmic proteins followed changes in K more closely. The RNA:DNA ratio in white muscle did not reflect changes in K or changes in growth rates.

Growth, starvation and enzyme activity in white muscle of atlantic cod: at what point do muscle metabolic capacities change?

“…The present study suggests that this may only apply when condition and growth rate covary ( Fig. 1 in Dutil et al, 1998). This is not an unreasonable assumption in prolonged experiments ( Fig.…”

“…None of these studies compared the response of muscle metabolic capacities to ascending and descending growth and condition trajectories. Dutil et al (1998) examined the metabolic activities of several tissues and considered both condition and growth effects in fish with positive and negative growth trajectories. CCO activity in the intestine consistently matched growth rate trajectories.…”

Does temperature preference relate to the anaerobic capacity of Atlantic cod (Gadus morhuaL.) with different haemoglobin phenotype?

“…Mean LDH levels were 162.29/5.0 and 275.99/ 6.4 IU g (1 wet mass (mean9/SEM) at 6 and 148C, the overall Q 10 was 2.04 and the current kinetic activities are comparable to previously reported values at similar temperatures (Couture et al 1998;Dutil et al 1998;Martinez et al 1999;Martinez et al 2003). It appears, therefore, that no correlation exists between the anaerobic potential (i.e.…”

Seasonal and Regional Variations in Metal Contamination and Condition Indicators in Yellow Perch (Perca flavescens) along Two Polymetallic Gradients. III. Energetic and Physiological Indicators

“…This result may be related to the lower growth, fish condition, and generally smaller size of S fish compared to RN fish (Pyle et al 2008). Indeed, muscle protein concentrations have been associated with higher growth and condition in yellow perch and other fish species (Guderley et al 1996;Dutil et al 1998;Audet and Couture 2003). Higher liver protein content in S fish could indicate that these fish invest more in biological processes other than muscle growth (such as metal detoxification).…”