... a 60-day experiment in winter (12°C) or summer (20°C) conditions under natural photoperiod. In addition, we measured mitochondrial respiration of red muscle fibres, biometric variables and energy reserves of individuals sampled at 30 and 60 days. This revealed that winter food deprivation elicits...

...) and swimming performance [critical swimming speed ( U crit ) and cost of transport (COT)] were assessed. In addition, enzyme activities [citrate synthase (CS), cytochrome c oxidase (COX) and lactate dehydrogenase (LDH)] and mitochondrial respiration were examined in red muscle fibres. We found that acclimation...

... muscle strips and myocardial trabeculae, and efficiency (net work/energy consumed) was measured for trabeculae, from cold (6°C) and warm (15°C) acclimated fish at temperatures from 2 to 26°C. The mass-specific net power produced by char red muscle was greater than in salmon, by 2-to 5-fold depending...

..., showing that it was partly catalyzed by xanthine oxidoreductase. The present study is the first to examine NO metabolite and Mb levels in both red and white muscle in a hypoxia-tolerant lower vertebrate. We found considerably higher Mb concentrations in red muscle than in white muscle, and the level...

... the series for red fibres and increased for white fibres. † Present address: School of Life Sciences, University of Hertfordshire, College Lane, Hatfield, Hertfordshire AL10 9AB, UK * Author for correspondence ( [email protected] ) 11 2 2010 © 2010. 2010 red muscle red...

... in lateral red muscle( b =0.5). Although oxidative enzymes showed negative allometry in red muscle ( b =–0.01 to –0.02), mass-specific myoglobin content scaled positively ( b =0.7). Capillary to fibre ratio of red muscle was higher in larger (1.42±0.15) than smaller (1.20±0.15)fish, suggesting progressive...

... along the body at a relatively high velocity of 1.7 L per tail beat period, and a significant phase shift(31±4°) occurred between muscle shortening and local midline curvature, both suggesting red muscle power is directed posteriorly, rather than causing local body bending, which is a hallmark...

...Leonardo Magnoni; Jean-Michel Weber SUMMARY Fish endurance swimming is primarily powered by lipids supplied to red muscle by the circulation, but the mechanism of delivery remains unknown. By analogy to mammals, previous studies have focused on non-esterified fatty acids (NEFA bound to albumin...

... and power output. Based on later EMG onset and offset times measured in swimming mako sharks mentioned above, it is hypothesized that red muscle from mako sharks will produce power at greater cycle frequencies than the red muscle of leopard sharks, at a given temperature. Five leopard sharks...

... of RM. However, A. superciliosus and A. pelagicus differ from A. vulpinus in that they do not possess the medial and anterior RM arrangement that would likely facilitate metabolic heat conservation (RM endothermy). Table 1. Shark fork length ( FL ), body mass, red muscle (RM) position,RM cross...

...-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...

... myotome red muscle aerobic capacity myoglobin muscle ultrastructure scaling allometry Lamnidae Scombridae Isurus Lamna Alopias Mustelus Triakis Prionace A marked evolutionary convergence has been demonstrated for the lamnid sharks (order Lamniformes; family Lamnidae...

... explain such links. The condition factor [(somatic mass × fork length -3 )×100] of starved cod was 0.54±0.1 whereas that of fed cod was 0.81±0.1. In white and red muscle, we measured four glycolytic enzymes: phosphofructokinase (PFK), pyruvate kinase (PK), creatine kinase (CK) and lactate dehydrogenase...

...Jeff G. Richards; Ashley J. Mercado; Cheryl A. Clayton; George J. F. Heigenhauser; Chris M. Wood SUMMARY A biochemical approach was employed to examine the oxidative utilization of carbohydrate and lipid in red muscle of rainbow trout ( Oncorhynchus mykiss ) during sustained swimming at 30 and 60...

...F. Lou; N. A. Curtin; R. C. Woledge SUMMARY Maximum isometric tetanic force produced by bundles of red muscle fibres from dogfish, Scyliorhinus canicula (L.), was 142.4±10.3 kN m -2 ( N =35 fibre bundles); this was significantly less than that produced by white fibres 289.2±8.4 kN m -2 ( N =25...

...Douglas A. Syme; Robert E. Shadwick SUMMARY The mechanical power output of deep, red muscle from skipjack tuna ( Katsuwonus pelamis ) was studied to investigate (i) whether this muscle generates maximum power during cruise swimming, (ii) how the differences in strain experienced by red muscle...

...Diego Bernal; Chugey Sepulveda; Jeffrey B. Graham SUMMARY The mako shark ( Isurus oxyrinchus ) has specialized vascular networks (retia mirabilia) forming counter-current heat exchangers that allow metabolic heat retention in certain regions of the body, including the aerobic, locomotor red muscle...

... muscle mechanics red muscle white muscle kinetics power work. Undulatory swimming fish use a backward-travelling wave of lateral curvature to propel themselves through the water. This mechanical wave corresponds to the occurrence of rhythmic, nearly sinusoidal, changes in length...

...David J. Coughlin ABSTRACT Steady swimming in fishes is powered by the aerobic or red muscle, but there are conflicting theories on the relative roles of the anterior and posterior red muscle in powering steady swimming. To examine how red muscle is used to power steady swimming in rainbow trout...

... cruising speeds in a large water tunnel treadmill. In both species, the onset of red muscle activation proceeds sequentially in a rostro-caudal direction, while the offset (or deactivation) is nearly simultaneous at all sites, so that EMG burst duration decreases towards the tail. Muscle duty cycle at each...