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

This Article 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 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 Yang, T. H. Articles by Somero, G. N. Search for Related Content PubMed Articles by Yang, T. H. Articles by Somero, G. N.

Journal of Experimental Biology, Vol 181, Issue 1 213-232, Copyright © 1993 by Company of Biologists

JOURNAL ARTICLES

EFFECTS OF FEEDING AND FOOD DEPRIVATION ON OXYGEN CONSUMPTION, MUSCLE PROTEIN CONCENTRATION AND ACTIVITIES OF ENERGY METABOLISM ENZYMES IN MUSCLE AND BRAIN OF SHALLOW-LIVING (SCORPAENA GUTTATA) AND DEEP-LIVING (SEBASTOLOBUS ALASCANUS) SCORPAENID FISHES

T. H. Yang and G. N. Somero

The effects of feeding and fasting were examined on the deep-living short-spine thornyhead (Sebastolobus alascanus) and the confamilial shallow-living spotted scorpionfish (Scorpaena guttata) to determine whether the low metabolic rate of the deeper-living species was in part a consequence of food deprivation in its habitat. Laboratory acclimation for periods of 90-115 days under either ad libitum feeding or complete fasting did not lead to similar rates of respiration in individuals of the two species held under identical conditions. Respiration of fish fed ad libitum was 52 % (S. guttata) or 68 % (S. alascanus) higher than for fasted fish of the same species. Furthermore, the metabolic rates of freshly collected specimens of S. alascanus resembled those of laboratory-fasted fish. In white skeletal muscle, both total protein concentration and the activities of four enzymes of ATP metabolism, lactate dehydrogenase (LDH) and pyruvate kinase (PK) of glycolysis, malate dehydrogenase (MDH) and citrate synthase (CS, a citric acid cycle indicator), were lower in S. alascanus than in S. guttata. Within a species, protein concentration and activities of the four enzymes in white muscle, but not in brain, were higher in fed than in starved fish, although these differences were greater in S. alascanus than in S. guttata. During fasting, LDH and PK activity in white muscle of S. alascanus decreased much more than MDH and CS activity; decreases in enzyme activities in red muscle were smaller than those in white muscle. Activities of enzymes in white skeletal muscle of field-collected S. alascanus generally resembled those of the fasted specimens. In contrast, red muscle of field- collected S. alascanus, compared with that of either fed or starved laboratory-held specimens, had a highly glycolytic poise (high LDH and PK activities relative to MDH and CS activities), which may suggest that muscle enzyme activities in the field-collected fish reflect adaptation to the low oxygen level in its adult habitat, the oxygen minimum layer. The strong correlations found between tissue biochemical properties and respiration rate allow us to develop a predictive index for metabolic rate from simple biochemical analyses, e.g. white muscle protein content or CS activity. We conclude that the low metabolic rate of S. alascanus is due to at least four depth-related factors: reduced abundance of food, low temperature, low ambient oxygen concentration and darkness, which may select for reduced locomotory activity.

This article has been cited by other articles:

				M. Zakhartsev, T. Johansen, H. O. Portner, and R. Blust Effects of temperature acclimation on lactate dehydrogenase of cod (Gadus morhua): genetic, kinetic and thermodynamic aspects J. Exp. Biol., January 1, 2004; 207(1): 95 - 112. [Abstract] [Full Text] [PDF]

				E. P. Dahlhoff, J. H. Stillman, and B. A. Menge Physiological Community Ecology: Variation in Metabolic Activity of Ecologically Important Rocky Intertidal Invertebrates Along Environmental Gradients Integr. Comp. Biol., August 1, 2002; 42(4): 862 - 871. [Abstract] [Full Text] [PDF]