Voluntary Swimming Research Articles

The Relationships among Sprint Performance, Voluntary Swimming Activity, and Social Dominance in Juvenile Rainbow Trout

The specific objectives of this study were to determine whether sprint performance in juvenile rainbow trout is correlated with either voluntary swimming activity or aggressive behaviors and to determine the reciprocal: the effect of swimming activity and aggression on sprint performance. Sprint performance was assessed by rapidly accelerating trout (5-7-cm fork length) to a fixed velocity (40, 42, or 45 cm s(-1)) and then holding them at that velocity until fatigue. There was considerable interindividual variation in sprint performance not explained by variations in body size, but intraindividual performance was highly repeatable over at least 2 mo. Voluntary swimming was measured as the frequency of transits (voluntary transit activity, VTA) between two identical tanks via a connecting channel with two different flow regimes: zero or minimum velocity (0 or 2.5 cm s(-1)) and high velocity (84 cm s(-1)). There was a strong correlation between sprint performance and VTA in minimal current but no correlation in high current. Furthermore, sprint performance did not predict the outcome of dominance encounters. Experience with rapid acceleration, especially when voluntary, led to a pronounced improvement in sprint performance in proportion to the number of acceleration events. Social dominance encounters had a more complex effect: a significant reduction in sprint performance in previously high-performance sprinters and the reverse for low performers. We propose that there are four independent axes of interindividual variation in juvenile rainbow trout: spontaneous and rheotaxis-stimulated locomotor activity, aggressive activity, and the trainability of sprint performance. The independence of these axes has the potential to produce a much larger diversity in behavioral and ultimately physiological phenotypes than would be produced if the axes were linked.

Crossed Commissural Pathways in the Spinal Hindlimb Enlargement Are Not Necessary for Right–Left Hindlimb Alternation During Turtle Swimming

We examined the coordination between right and left hindlimbs during voluntary forward swimming in adult red-eared turtles, before and after midsagittal section of the spinal cord hindlimb enlargement (segments D8-S2) or the enlargement plus the first preenlargement segment (D7-S2). Our purpose was to assess the role of crossed commissural axons in these segments for right-left hindlimb alternation during voluntary locomotion. Midsagittal splitting severed commissural fibers and separated the right and left halves of the posterior spinal cord. Adult turtles (n = 9) were held by a band clamp around the shell in a water-filled tank while digital video of forward swimming was recorded from below and computer analyzed with motion analysis software. In a subset of these animals (n = 5), we also recorded electromyograms from hip extensor and/or hip flexor muscles on both sides. Surprisingly, splitting spinal segments D8-S2 or D7-S2 did not affect the strength of out-of-phase coordination between right and left hindlimbs, although hindlimb movement amplitudes were reduced compared with presurgical controls. These results show that commissural axons in the hindlimb enlargement and preenlargement cord are not necessary for right-left hindlimb alternation during voluntary swimming. We suggest that alternating propriospinal drive from the right and left sides of the forelimb enlargement maintains the out-of-phase coordination of right and left hindlimbs in the bisected-cord preparation. Our data support the hypothesis that descending propriospinal (forelimb-hindlimb) and crossed commissural (hindlimb-hindlimb) spinal cord pathways function together as redundant mechanisms to sustain right-left hindlimb alternation during turtle locomotion.

Cardiorespiratory performance during prolonged swimming tests with salmonids: a perspective on temperature effects and potential analytical pitfalls

A prolonged swimming trial is the most common approach in studying steady-state changes in oxygen uptake, cardiac output and tissue oxygen extraction as a function of swimming speed in salmonids. The data generated by these sorts of studies are used here to support the idea that a maximum oxygen uptake is reached during a critical swimming speed test. Maximum oxygen uptake has a temperature optimum. Potential explanations are advanced to explain why maximum aerobic performance falls off at high temperature. The valuable information provided by critical swimming tests can be confounded by non-steady-state swimming behaviours, which typically occur with increasing frequency as salmonids approach fatigue. Two major concerns are noted. Foremost, measurements of oxygen uptake during swimming can considerably underestimate the true cost of transport near critical swimming speed, apparently in a temperature-dependent manner. Second, based on a comparison with voluntary swimming ascents in a raceway, forced swimming trials in a swim tunnel respirometer may underestimate critical swimming speed, possibly because fish in a swim tunnel respirometer are unable to sustain a ground speed.

Water retention in the plumage of diving great cormorants Phalacrocorax carbo sinensis

Cormorants are assumed to have a “partially wettable” plumage as a mechanism to reduce buoyancy while swimming underwater. This assumption is mainly based on 3 observations: 1) the volume of air in the plumage of submerged carcasses is small compared to other water birds, 2) cormorants assume a “wing drying” posture when they exit the water, and 3) the feather structure of the plumage. An alternative mechanism to reduce buoyancy is to release air out of the plumage by ptilomotion without allowing water to penetrate. How wet cormorants actually get is an open issue that has important implications for the energy budget of these warm blooded aquatic predators. Here we report empirical measurements on the amount of water retained in the plumage of live great cormorant Phlacrocorax carbo sinensis during voluntary swimming and diving in an experimental design that simulates a foraging diving bout. The amount of water retained in the plumage increased as a function of time spent in water. However the birds limited their dive bouts to less than 18 minutes so that the added mass of retained water did not exceed 6% of their body mass. This maximal level of water retention is estimated to reduce the buoyancy of the dry bird by 18%. This maximal level is also similar to measurements of water retention of carcasses and suggests that measurements preformed on carcasses yield only the upper level of water absorption while live birds slow down water penetration, allowing longer periods of foraging.

Endurance swimming of diploid and triploid Atlantic salmon

When groups of diploid (mean ± s.e. fork length, LF) 33·0 ± 1·4 cm and triploid (35·3 ± 0·5 cm) Atlantic salmon Salmo salar were forced to swim at controlled speeds in a carefully monitored 10 m diameter ‘annular’ tank no significant difference was found between the maximum sustained swimming speeds (Ums, maintainable for 200 min) where the fish swam at the limit of their aerobic capability. Diploids achieved 2·99 body lengths per second (bl s−1)(0·96 m s−1) and triploids sustained 2·91 bl s−1(1·02 m s−1). The selection of fish for the trials was based on their ability to swim with a moving pattern projected from a gantry rotating at the radius of the tank and the selection procedure did not prove to be significant by ploidy. A significant difference was found between the anaerobic capabilities of the fish measured as endurance times at their prolonged swimming speeds. During the course of the experimentation the voluntary swimming speed selected by the fish increased and the schooling behaviour improved. The effect of the curvature of the tank on the fish speeds was calculated (removing the curved effect of the tank increased the speed in either ploidy by 5·5%). Implications of the endurance times and speeds are discussed with reference to the aquaculture of triploid Atlantic salmon.

Effects of capture and transmitter attachments on the swimming speed of large juvenile lemon sharks in the wild

The swimming speed of seven large juvenile lemon sharks Negaprion brevirostris following attachment of an external speed‐sensing ultrasonic transmitter was significantly higher during the first 18 h after release compared to the average swimming speed obtained >48 h after release. The external speed‐sensing transmitter can be used to monitor the voluntary swimming speed of large fishes in the field, but data during the first 24 h period should be excluded from analysis of natural speeds, at least from species similar in behaviour to N. brevirostris.

Swimming behaviour of winter flounder ( Pleuronectes americanus) on natural fishing grounds as observed by an underwater video camera

Swimming behaviour of winter flounder ( Pleuronectes americanus) was recorded near baited hooks on natural fishing grounds using an underwater video camera. Winter flounder were observed to stay on or very close to the seabed, never rising to more than 0.6 m off bottom during 1 month of observation. Winter flounder were recorded to take bait actively at temperatures as low as −1.2 °C. Movement of winter flounder was characterised by a period of swimming off seabed followed by a period of resting on the seabed. The proportion of time swimming off seabed as opposed to resting on the seabed was positively related to water temperature. Flounder spent an average of 32% of time in swimming when at −1.2 °C compared with 67% when at 4.4 °C. Voluntary swimming speed of the flounder during the period of swimming was lower at lower temperatures. An average swimming speed of 0.52 body lengths per second (L s −1) at −1.2 °C was recorded compared with 0.95 L s −1 at 4.4 °C. Overall rate of movement was reduced by three-fold when water temperature fell from 4.4 to −1.2 °C. The reduced rate of movement at lower temperatures is discussed in relation to potential fishing area of fixed fishing gears such as gillnets.

Energetics of Surface Swimming in Brandt’s Cormorants (Phalacrocorax Penicillatus Brandt)

The energy requirements of Brandt's cormorants (Phalacrocorax penicillatus) during surface swimming were measured in birds swimming under a metabolic chamber in a water flume. From the oxygen consumption recordings, we extrapolated the metabolic rate and cost of transport at water speeds ranging from 0 to 1.3 m s(-)(1). In still water, the birds' mean mass-specific rate of oxygen consumption ( V(O2)) while floating at the surface was 20.2 ml O(2 )min(-)(1 )kg(-)(1), 2.1 times the predicted resting metabolic rate. During steady-state voluntary swimming against a flow, their V(O2) increased with water speed, reaching 74 ml O(2 )min(-)(1 )kg(-)(1) at 1.3 m s(-)(1), which corresponded to an increase in metabolic rate from 11 to 25 W kg(-)(1). The cost of transport decreased with swimming velocity, approaching a minimum of 19 J kg(-)(1 )m(-)(1) for a swimming speed of 1.3 m s(-)(1). Surface swimming in the cormorant costs approximately 18 % less than sub-surface swimming. This confirms similar findings in tufted ducks (Aythya fuligula) and supports the hypothesis that increased energy requirements are necessary in these birds during diving to overcome buoyancy and heat loss during submergence.

Influence of Temperature, Body Size, and Inter-Individual Variation on Forced and Voluntary Swimming and Crawling Speeds in Nerodia sipedon and Regina septemvittata

Influence of Temperature, Body Size, and Inter-Individual Variation on Forced and Voluntary Swimming and Crawling Speeds in Nerodia sipedon and Regina septemvittata

What a drag it is getting cold: partitioning the physical and physiological effects of temperature on fish swimming

The influence of temperature-induced changes in water viscosity on the swimming performance and kinematics of larval Atlantic herring (Clupea harengus) was examined using high-speed video recording. The physical effects of viscosity were measured separately from the physiological (Q10) effects of temperature by increasing the viscosity using methyl cellulose. Voluntary swimming speeds of large larvae (18.2 mm total length) were characterized by Reynolds numbers based on length (ReL) between 100 and 500 and varied with temperature and viscosity. Speeds of small larvae (9.6 mm) at ReL between 25 and 125 were strongly affected by viscosity, but virtually unaffected by temperature at equal viscosities. Speeds of large larvae were modulated by transverse tail speed. Small (viscosity-dominated) larvae altered both transverse tail speed and tail amplitude to vary their swimming speed. Stride lengths for both sizes of larvae followed predictions for viscous-regime swimming until ReL>450. The combined data suggest that the viscous hydrodynamic regime for larval herring extends to at least ReL=300 and that viscosity could be important up to ReL of approximately 450. Because the physical effects of viscosity supplement the physiological effects of temperature on locomotor performance (when ReL is below approximately 300), indices such as Q10 can greatly overestimate the dependence of physiological processes on temperature, as demonstrated by an example.

Respiration rate of adult pilchard Sardinops sagax in relation to temperature, voluntary swimming speed and feeding behaviour

Respiration rate of adult pilchard Sardinops sagax in relation to temperature, voluntary swimming speed and feeding behaviour

The Effect of Catecholamines, Substance P and Vasoactive Intestinal Polypeptide on Blood Flow to the Gut In the Dogfish Squalus Acanthias

ABSTRACT The effects of adrenaline, noradrenaline, substance P and vasoactive intestinal polypeptide (VIP) on dorsal aortic blood pressure, coeliac artery blood flow and heart rate were studied in unrestrained dogfish, Squalus acanthias. Changes in the coeliac vascular bed were calculated from these variables. Perfused tail preparations were used to study the effects of the various drugs on the somatic vascular bed. Corrosion casts were made to study the gross architecture of the coeliac vascular bed. Adrenaline and noradrenaline increased dorsal aortic pressure and reduced the coeliac artery blood flow. Adrenaline caused a small increase in heart rate while noradrenaline caused a small decrease. Both drugs increased the resistance in the coeliac vascular bed. VIP increased dorsal aortic pressure, heart rate and resistance in the coeliac vascular bed. Substance P caused an increase in heart rate, cardiac output and, in particular, in coeliac artery blood flow; dorsal aortic pressure was simultaneously reduced. Voluntary swimming or fright immediately caused a pronounced reduction in blood flow in the coeliac artery, even though cardiac output and dorsal aortic pressure increased. It is concluded that adrenergic mechanisms and possibly VIP are involved in reducing the blood flow to the gut, while substance P increases the flow to the gut.

Voluntary Swimming Speeds of Two Species of Large Carcharhinid Sharks

Voluntary Swimming Speeds of Two Species of Large Carcharhinid Sharks