The goal of the present study was to compare the effect of temperature on contraction kinetic parameters of fish muscle with its effect on oscillatory work. In particular we studied the effect of stimulus train duration or duty cycle (the fraction of the imposed length change that the muscle was sti...

The goal of our experiment was to elucidate the effect of stimulus duty cycle (the percentage of the cycle that the muscle was stimulated), phase (the relative timing of the imposed sinusoidal length change and stimulation), and muscle cycle frequency (the speed at which the muscle was cycled) on wo...

Stimulus trains of varying pulse number and pulse frequency were applied to the isolated pectoral adductor muscle of the sunfish Lepomis gibbosus. The number of pulses varied from 1 to 70, and the pulse frequency varied from 10 to 500 Hz. Muscle was continuously cycled at 2 Hz, and work was measured...

We examined the thermal biology of free-ranging terrestrial eastern foxsnakes (Elaphe gloydi Conant, 1940) that were voluntarily swimming in cold water during spring, in Georgian Bay, Ontario, Canada. Using temperature-sensitive radiotelemetry, we recorded body temperatures of foxsnakes during 12 co...

Isometric twitch and tetanus parameters, force-velocity curves, maximum shortening velocity (V-max) and percentage relaxation between stimuli (%R) across a range of stimulus frequencies were determined for a muscle used during call production (the tenser chordarum) and a locomotor muscle (the sartor...

Rainbow trout, Oncorhynchus mykiss, were injected with an adrenergic agonist. an adrenergic antagonist, or a cholinergic antagonist, via a dorsal aorta cannula. Spleen size and haemoglobin content were measured at rest and, for antagonists, following an air exposure stress. Injection of phentolamine...

Fish were sampled individually, at rest, following air exposures of up to 8 min, during recovery from a 5 min air exposure or after a 5 minute chase. The spleen was photographed in vivo at rest and following 5 min air exposure in one fish. The effect of individual versus serial sampling from the sam...

Critical swim speed (U(crit)) measurements show that trout (Oncorhynchus mykiss) with an intact spleen perform aerobic exercise better than those without (control: U(crit) = 2.19 body lengths/s; splenectomized: U(crit) = 1.84 body lengths/s). Their better performance is correlated with higher blood ...

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We present the first measurements of routine oxygen uptake (VO2) of the bloater (Coregonus hoyi), including the effects of temperature and hydrostatic pressure. For temperature experiments, ten 24 hour trials were conducted each at 10.5°C and 7°C, using flow-through respirometry. Average routine V...

The force-velocity relation during oscillatory work was compared with that measured in the traditional way with quick release and force clamps using toad sartorius, frog sartorius, and mouse soleus muscles. Plotting the force and corresponding velocity data in this way produces a 'power-loop&ap...