Average Swimming Speed Research Articles

Power requirement of swimming in chinook salmon and Atlantic salmon and implications for food conversion and growth performance

Body dimensions and swimming speeds of Atlantic salmon ( Salmo salar) and chinook salmon ( Oncorhynchus tshawytscha), ranging in weight from less than 1 to over 6 kg, were used to calculate the power needed to overcome drag. Fish were kept in 15 m×15 m×15 m deep cages, stocked under typical industrial conditions and fed to apparent satiation by broadcasting feed over the water surface. The average swimming speed for both species was 0.68 m s −1. Power required for swimming increased as the fish grew, and at a weight of ∼1.25 kg, fish changed from using available energy for long distance travelling to carrying a greater amount of weight for a shorter distance. The average profile drag acting on chinook salmon was significantly higher than on Atlantic salmon, principally because the girth of a chinook salmon was significantly larger than the girth of an Atlantic salmon of similar mass. This difference in energy expenditure due to drag explains over 20% of the observed difference in the feed conversion ratios of the two species. The selection of fish with a more streamlined body shape as breeding stock could improve the economics of chinook salmon cultivation. The techniques outlined herein can be used (a) to evaluate suitability of other species and sites for aquaculture, (b) as criteria in a breeding program, and (c) for setting criteria for permissible velocities in fisheries projects.

Can stationary bottom split-beam hydroacoustics be used to measure fish swimming speed in situ?

We used split-beam hydroacoustics (Simrad EY500, 70 kHz) as a method for estimating fish swimming speed in situ. The method was first evaluated in the field using underwater video cameras (stereocinematographic method, SCG) to estimate accurate fish swimming speeds. The mean and distribution of swimming speeds of 15-cm brook trout ( Salvelinus fontinalis) obtained by the two methods were not statistically different (average 17.8 cm s –1with split-beam and 18.6 cm s –1with SCG). We then used the split-beam technique to measure swimming performance in situ for fish assumed to be yellow perch ( Perca flavescens) and alewives ( Alosa pseudoharengus) in two lakes in New York State, USA. The measured swimming speeds ranged from 0.5 to 6 body length (BL) per second for juvenile and adult fish. Other laboratory studies on swimming speeds have reported values in the same range. However, measured swimming speeds for smaller fish were unrealistically high (2–32 BL s −1) Advantages of the split-beam method are the ability of measuring swimming speed independently of visibility, with minimal disturbance and at large distances. Disadvantages are the inability to distinguish species observed and some variance in target location, which results in calculated average swimming speeds of 2.6 cm s –1 even for a stationary target.

Post-release behaviour of black marlin, Makaira indica , caught off the Great Barrier Reef with sportfishing gear

The post-release behaviour of eight black marlin (Makaira indica), caught by standard sportfishing techniques off the Great Barrier Reef, Australia, was investigated using ultrasonic telemetry. Five marlin between 100 and 420 kg were successfully tracked for periods of 8 to 27 h. Of the three others tagged, one was killed by a shark and two shed their tags, probably as the result of poor attachment. The black marlin spent most of their time within 10 m of the surface, both day and night. During the day, however, they also spent some time between 40 and 140 m depth. They rarely penetrated the thermocline, and then only briefly, remaining at temperatures no more than 8 C° below that of surface waters. The deepest dives were to 178 m. Four of the five marlin tracked, initially moved offshore before heading parallel to the shore, whereas the other marlin stayed close to the reef edge. The average mean swimming speeds over the ground for entire tracks ranged from 0.7 to 1.02 m s−1.

Influence of Prey Behavior on Selective Predation by Lake Trout (Salvelinus namaycush) under Laboratory Conditions

We explored whether certain behaviors by prey fish species contributed to selective predation by lake trout (Salvelinus namaycush). Schooling behavior, reactive distance, and predator attack and prey escape swimming speeds were examined for alewife (Alosa pseudoharengus), bloater (Coregonus hoyi), rainbow smelt (Osmerus mordax), and yellow perch (Perca flavescens). In addition, two- and three-prey species combinations were presented to lake trout to determine if a particular prey species was utilized to a greater extent than others and to observe which specific behaviors or other prey characteristics could account for their greater utilization. There was little difference in percent capture of various prey species and no significant difference (p > 0.05) in escape swimming speeds or attack swimming speeds. However, maximum attack swimming speeds by the lake trout exceeded the maximum escape swimming speeds of prey. Average escape swimming speeds ranged from 2.5 to 2.9 m/sec, and average attack swimming speeds ranged from 2.8 to 3.1 m/sec. Reactive distances were not important since more than 90% of the prey were captured before they had time to react. Prey reactive distances ranged from 0.0 to 1.0 m. Even a small reactive distance and an average escape swimming speed allowed the prey to get close to the aquarium wall where lake trout would not attack. In two-species trials, bloater was preferred over yellow perch (p < 0.025) in one trial. In three-species trials, lake trout foraged preferentially (p < 0.05) on alewife when compared to bloater and yellow perch in four of five trials. The bloater appeared as the second most utilized species although there was no significant difference (p > 0.05) in utilization between bloater and yellow perch. Lake trout were probably reacting to the continuous movement and tight schooling of alewives in the water column.

Preliminary description of swimming activity and estimation of swimming speed of saithe (Pollachius virens) at one location in the North Sea

Individual saithe were tracked with a split-beam echosounder, while the vessel was drifting, in the area around Eigersundbank in the North Sea and their swimming speed estimated. The average swimming speed was approximately 4 and 1 body lengths per second for small saithe (20–30 cm) and saithe &amp;gt;70 cm, respectively, and a significant inverse relationship between length of the saithe and swimming speed was found. There was clear evidence of diurnal variation in swimming speed of small saithe, as the swimming speed was significantly higher during night (18–06 h) than during day (06–18 h). The number of observations on saithe &amp;gt;70 cm was too small to compare day and night swimming speeds. Although the results indicate higher swimming speeds of saithe in the demersal layer compared to pelagic saithe, significant differences were not found. The duration of acoustic observation time was 36–56 min per 4-h sampling interval during the 24-h cycle. A total of 278 series of saithe were selected, which, according to selection criteria, were accepted as representing tracking of single fish over two pings or more. The species identify of the targets tracked acoustically was verified by trawling in the layers investigated.

Swim speeds and energy use of upriver-migrating sockeye salmon (Oncorhynchus nerka): role of local environment and fish characteristics

We used electromyogram (EMG) radiotelemetry to assess swimming activity (e.g., swim speeds), behaviour, and migration speeds (e.g., ground speeds) of individual adult sockeye salmon (Oncorhynchus nerka) migrating through several reaches of the Fraser and Nechako rivers in British Columbia. Using a laboratory swim flume and volitionally swimming adult fish carrying EMG transmitters, we developed relationships between EMG pulse intervals and swim speeds. A bioenergetics model was used to estimate reach-specific energy use per metre for each individual based on the average swim speed, migration time, body size, and river temperature. Migration was most energetically efficient (i.e., migration costs per unit distance traveled were relatively low) for females compared with males, large males compared with small males, and 1995 males compared with 1993 males. In all three cases, differences in swim speed patterns were primarily responsible for differences in energy use. For both sexes and in both years, migrations through reaches that contained a constriction (caused by an island, gravel bar, or large rock outcropping) were energetically inefficient compared with that through reaches with no constrictions. The high energetic costs at constrictions seem to result from long travel times probably caused by turbulent flow patterns that may generate confusing migrational cues.

Evaluation of empirical statistical models for analyzing swimming speeds of teleost fishes

Average swimming speeds attained for eight, discrete distances were determined for 10 teleost fishes: Atlantic croaker, bluegill sunfish, channel catfish, goldfish, hardhead sea catfish, large‐mouth bass, pigfish, pinfish, sheepshead porgy and striped burrfish. Swimming speeds in cm s−1 were analyzed by linear, quadratic, cubic and quartic regression, logio transformations, and by fitting exponential, geometric (power function), hyperbolic and logistic models by linear approximations. Swimming speeds in body lengths s −1 (BLS) were analyzed by linear, quadratic, cubic and quartic regression. The “best” method of analysis is quadratic regression for all species for both measures of swimming speed. Regression using BLS, however, provided improved r2% compared to regression using cm s−1. The wide range in morphology represented by these species was expected to yield a number of species‐specific models. The lack of diversity in these modelling results is attributed to trade‐offs and compromises in the functional designs, amounts of muscle mass as a percentage of body mass, and longitudinal depth distributions of the species.

Behavioral interactions between coho (Oncorhynchus kisutch) and chinook salmon (Oncorhynchus shawytscha) and prey fish species

Abstract— The predator‐prey behavioral interactions between two salmon species, coho salmon (Oncorhynchus kisutch) and chinook salmon (Oncorhynchus tshawytscha), and their prey species were examined under laboratory conditions. These behaviors were studied to determine the bases for prey selection by salmon in Lake Michigan and ultimately facilitate predictions on shifts or changes in salmon diets. Chinook and coho salmon captured all prey items in the open water portion of the aquarium, and they had similar attack behaviors. Average attack swimming speeds varied from 2.6 to 3.6 m/s, and average escape swimming speeds varied from 2.6 to 2.9 m/s. There were no significant differences in attack swimming speeds and escape swimming speeds. There was a significant difference in median reactive distances between the prey captured and those that escaped. There was no reactive distance (0.00 m) for 96% and 98% of the successfully captured prey by chinook and coho salmon, respectively. Only 4% and 10% of the unsuccessful attacks by chinook and coho salmon, respectively, had no reactive distance (0.00 m). Salmon would repeatedly attack a school and capture individuals separated from the school. Alewives, bloaters and fathead minnows were easy prey because they remained in the open water portion of the aquarium and stayed in schools until only a few individuals remained. The schooling behavior of spottail shiners and emerald shiners was an effective anti‐predation tactic against salmon attacks. After some experience with yellow perch, salmon were reluctant to attack them and would often break off attacks on them. When coho salmon were presented with different proportions of bloaters and yellow perch, they significantly attacked and captured bloaters in preference to yellow perch.

The influence of turbidity on larval walleye, Stizostedion vitreum, behavior and development in tank culture

The behavior and development of larval walleye, Stizostedion vitreum, cultured in clear and turbid water in laboratory aquaria are compared from hatch to 17 days post-hatch. Significant differences ( P ≤ 0.05) in larval distribution and swimming speed were observed. In clear water, larvae showed a strong association with the sides of the aquaria, but in tanks with turbid water, larvae avoided the sides of the aquaria. Larvae in turbid water had greater average swimming speeds, faster growth rates, and improved gas bladder inflation (GBI) than larvae cultured in tanks with clear water. There were no significant differences between the two treatments in larval survival or cannibalism. Larval viability (survival x GBI) was three times greater in turbid water (19.0%) than in clear water (5.7%). The improved performance and viability in turbid water are attributed to the changes in larval distribution as a consequence of larval reaction to diffused light in turbid water.

Global ischemic neuronal damage relates to behavioural deficits: a pharmacological approach

Global cerebral ischemia leads morphologically to selective neuronal damage in the CA1 sector of the hippocampus and in the striatum and functionally to a deficit in spatial learning and memory in the water maze. The results of earlier studies which examined the relationship between neuronal damage and the deficits in the water maze were not clear cut. It has been observed, however, that neuroprotection reduces both the deficits in the water maze as well as the neuronal damage. The present study therefore approached the relationship between the neuronal damage and the deficits in water maze using pharmacological means. Global cerebral ischemia was induced in male Wistar rats by four-vessel occlusion for 20 min. Ischemic rats were treated with the N-methyl- d-aspartate receptor antagonist dextromethorphan, 50 mg/kg, with the calcium antagonist levemopamil, 30 mg/kg, with the radical scavenger EPC-K1, 10 mg/kg, or with solvent. Treatment with dextromethorphan or levemopamil reduced the deficit in spatial learning by limiting the increase in swim distance due to ischemia. Both substances also reduced the deficit in spatial memory by minimizing the ischemia-induced reduction in time spent in the quadrant of the former platform postion during the probe trial. EPC-K1 had no influence on the ischemia-induced behavioural changes. Group comparisons demonstrated that the swim speed and the percentage of the swimming path along the sidewall were affected neither by ischemia nor by any of the treatments. Histological examination revealed neuronal damage in the hippocampus and in the striatum in all of the ischemic rats. Treatment with dextromethorphan or levemopamil reduced the hippocampal damage by 32% and 36%, respectively. In addition, dextromethorphan diminished the striatal damage about 78%. Correlation analysis demonstrated a correlation between the cumulative swim distance of all 20 escape trials and hippocampal damage ( r=0.65, P<0.001) but not between swim distance and striatal damage ( r=0.14, P=0.364). No correlation was found between quadrant time of the probe trial and either hippocampal damage ( r=−0.21, P=0.19) or striatal damage ( r=−0.02, P=0.889). The average percentage of the swimming path along the side wall related to the hippocampal damage ( r=0.28, P=0.035) but not to the striatal damage ( r=0.05, P=0.381). With respect to the average swim speed a correlation to striatal damage was observed ( r=−0.69, P<0.001) but not to hippocampal damage ( r=−0.15, P=0.168). These results clearly demonstrate that using the pharmacological approach it is possible to uncover certain correlations between functional deficits in the water maze and neuronal damage which are both due to global cerebral ischemia.

A VIDEO SONAR AS A NEW TOOL TO STUDY MARINE MAMMALS IN THE WILD: MEASUREMENTS OF DOLPHIN SWIMMING SPEED

ABSTRACTThe use of a multibeam sonar for fine‐scale studies of the foraging activity of bottlenose dolphins (Tursiops truncatus) was tested in a coastal environment where a group of 14 individuals is known to be resident. The sonar was set on a rubber boat and the signals were received continuously as the dolphins were foraging in a pass swept by strong tidal currents. These signals were recorded in HI 8 video standard. The system produced real‐time undistorted images of the dolphins and of their movements within the limits of the sonar beam (15° vertical width, 90° horizontal width, range set at 50 m). The average swimming speed relative to the bottom was 1.8 m ·sec−1 but swimming speed relative to the water was 2.2 m‐sec−1 when allowance was made for the average 1.2 m·sec−1 tidal current. Maximum swimming speed relative to the water was as high as 4.8 m·sec−1. It is estimated from studies of swimming energetics that continuously foraging in a current vein flowing at 1.2 m·sec1 would represent only small additional costs compared to foraging out of these currents. However, previous observations of the same pod have shown that these dolphins keep foraging in this site when current speed reaches 2.7 m·sec−1; under such circumstances, the cost of foraging in this site was calculated to increase by 96%. This suggests that foraging efficiency should be dramatically enhanced during rising tide since the dolphins consistently forage in these currents year round.

The sodium-driven polar flagellar motor of marine Vibrio as the mechanosensor that regulates lateral flagellar expression.

Certain marine Vibrio species swim in sea water, propelled by a polar flagellum, and swarm over surfaces using numerous lateral flagella. The polar and the lateral flagellar motors are powered by sodium- and proton-motive forces, respectively. The lateral flagella are produced in media of high viscosity, and the relevant viscosity sensor is the polar flagellum. The cell might monitor either the rotation rate of the flagellar motor or the mechanical force applied against the flagellum. To test these possibilities, we examined the effects of amiloride and its derivatives, which inhibit the rotation of the sodium-driven motor, on lateral flagellar gene (laf) expression in Vibrio parahaemolyticus. Phenamil, an amiloride analogue that inhibits swimming at micromolar concentrations, induced laf transcription in media devoid of viscous agents in a dose-dependent manner. The relationship between the average swimming speed and laf induction in the presence of various concentrations of phenamil was very similar to that observed when viscosity was changed. These results indicate that marine Vibrio sense a decrease in the rotation rate of (or the sodium influx through) the polar flagellar motor as a trigger for laf induction. Alternative mechanisms for laf induction are also discussed.

Estimation of fish activity costs using underwater video cameras

Swimming speed and activity costs of dace (Phoxinus eos × P. neogaeus) were estimated in the field using underwater video cameras. Activity costs were estimated by converting swimming speeds and the number of movements into swimming costs. Average swimming speed ranged from 6.7 to 12.2 cm.s−1 across 2 h periods and varied significantly among dates and time of day. The time spent swimming by dace ranged from 616 to 17 640 s 2 h−1. Activity costs per 2h period ranged from 2.1 to 4O.2J 2h−1 and were strongly correlated to the time spent swimming. Daily activity cost estimated using the cameras averaged 128.9J day−1 and was equivalent to 1.7 times the standard metabolic rate. Activity cost predicted using a bioenergetic model in conjunction with independent estimates of consumption and growth rates averaged 138.8J day−1. This study indicated that swimming characteristics and activity costs of dace varied significantly both within and among days. These analyses also indicated that equally valid activity costs for fish in the field can be estimated using video cameras and the difference between Consumption and growth rates.

Swimming behaviour of developmental stages of the calanoid copepod Temora longicornis at different food concentrations

The swimming behaviour of developmental stages of the marine calanoid copepod Temora longicornis was studied using 2-dimensional observations under a microscope and a 3-dimensional filming technique to analyze swimming mode, swimming speed and swimming trajectories under different food concentrations. The nauplii swam intermittently in a stop-and-go fashion. The swimming behaviour of the smallest feeding stage (N2) did not change with different food concentrations. The largest nauplius stages reacted to an increased food concentration by increasing the percentage of time spent swimming. All copepodid stages swam continuously their mouthparts moving nearly 100% of the time. Copepodids can therefore only increase their feeding effort by increasing their limb beat frequency. Adult females showed low swimming speeds at very low food concentrations, higher swimming speeds at intermediate concentrations and low swimming speeds at very high food concentrations. This agreed with expectations based on the optimal foraging theory. Males behaved differently from the females. Not only was the average swimming speed of males higher at similar food conditions, but they also maintained a very high swimming speed at very high food concentrations. This increased swimming activity in the males may be linked to a mate seeking strategy. Neither males nor females showed any obvious differences in turning behaviour at different food concentrations.

Influence of Sustained Exercise at Two Ration Levels on Growth and Thyroid Function of All-Female Chinook Salmon (Oncorhynchus tshawytscha) in Seawater

Duplicate groups of seawater-adapted 70-g all-female chinook salmon (Oncorhynchus tshawytscha) were held in flowing seawater (24–29‰; 8–12 °C) corresponding to swimming speeds (SS) of 0.5, 1.0, or 1.5 body lengths (bl)/s for 212 d. Fish were fed either a maximum satiating ration of 75% of maximum ration at each SS. Fish grew four- to fivefold during the study, but neither mean body weight, fork length, specific growth rate, condition factor, nor muscle morphometry was influenced by average SS. However, the SS of individually marked fish were negatively correlated with specific growth rate. At both rations, higher SS increased the internal tissue-carcass ratio, hepatosomatic index, and total body protein. More food was ingested at higher SS resulting in reduced feed efficiency. SS did not alter the plasma L-thyroxine (T4) concentration, but increased the plasma 3,5,3′-triiodo-L-thyronine (T3) concentration and T3/T4ratio. In part, this may reflect the greater food intake at higher SS. The reduced ration depressed all aspects of growth and at 212 d tended to depress both plasma T4and T3, but did not alter feed efficiency. We conclude that exercise over the range of 0.5–1.5 bl/s does not enhance growth, but reduces feed efficiency in seawater-adapted chinook salmon.

Amphipods on a deep-sea hydrothermal treadmill

Conspicuous swarms of a pardaliscid amphipod were observed at about 2520 and 2580 m depth in the East Pacific Rise vent field during dives with the submersible Alvin. Swarms occurred in association with mussels, clams and tubeworms, and were located above, and immediately downstream of cracks with emanating hydrothermal water. Numerical density sometimes exceeded 1000 individuals 1 −1, which is 3 orders of magnitude greater than any previous report on pelagic crustaceans from the deep sea. The amphipods, however, were not obligatory swarmers, and thin-layered shoals and scattered individuals were observed. Orientation of individuals was often polarized as they headed into the venting flow, swimming vigorously at 5–10 cm s −1 to maintain their position in the current. Retention within the preferred habitat requires an average swimming speed corresponding to the average current speed, suggesting a sustained swimming of > 10 body lengths s −1. These observations contrast with the general concept of low swimming activity in deep-sea crustaceans.

Cholinergic effects on spatial exploration and its memory.

In their first swim in an unfamiliar circular swimming pool, control rats showed declines in average swimming speed and in the time spent in the perimeter of the pool. Both declines were antagonized by the muscarinic antagonist scopolamine, but not by methylscopolamine, a muscarinic antagonist that crosses the blood-brain barrier only poorly, indicating that these declines depend upon central cholinergic activity. In the first minute of a second swim 3 days later, control rats spent a much longer time in the central region of the pool than in the first minute of the first swim. This modification of behaviour by previous experience suggests that a long-term memory of the first swim was formed. Scopolamine, but not methylscopolamine, administered before the first swim attenuated this modification of behaviour. Pilocarpine, administered shortly after scopolamine before the first swim, significantly normalized all the scopolamine-induced changes, whereas oxotremorine and arecoline normalized only habituation of perimeter preference; agonists administered alone decreased swimming speed and perimeter preference without affecting their rates of decline. The results suggest that in this test, different cholinergic mechanisms are involved in habituation of swimming speed and habituation of perimeter preference.

Motility characteristics and membrane integrity of cryopreserved human spermatozoa.

The motility characteristics of washed spermatozoa from 50 normal ejaculates were measured by time-lapse photography, before and after cryopreservation. Plasma membrane integrity was assessed by the hypo-osmotic swelling test and with the supravital fluorescent dye bisbenzimide (H33258). There was a marked decline in the percentage of progressively motile spermatozoa after cryopreservation, the extent varying widely among donors. Results were, however, consistent between different ejaculates from the same individual. The ability of spermatozoa to survive cryopreservation could not be predicted from the properties of the semen beforehand. The mean velocity of the spermatozoa was significantly reduced after freezing, but the lateral head displacement was unaltered. There was a significant reduction in the proportion of spermatozoa with intact plasma membranes after cryopreservation and the results of the hypo-osmotic swelling test and H33258 tests correlated closely. There was no correlation between the declines in the percentage of motile spermatozoa, or intact spermatozoa and the sperm velocity. We conclude that membrane rupture is not the sole cause of loss of motile spermatozoa during freezing and that the decrease in the proportion of motile spermatozoa is caused, at least in part, by a separate process from that responsible for the decrease in the average swimming speed of spermatozoa.

Diving depths of Shags Phalacrocorax aristotelis breeding on the Isle of May

Information on maximum dive depth and the time spent at various depths was obtained from 49 Shags Phalacrocorax aristotelis. On average, the maximum dive depth was 33–35 m; the overall maximum was 43 m. Shags dived repeatedly to the same depth and spent c. 55% of the time between 25 and 34 m which indicated that they were foraging close to the seabed. About 46% of the time underwater was spent foraging and 54% travelling. Average underwater swimming speed was 1.7‐1.9 m per second.

Speed and Direction of Swimming by Postlarvae of the American Lobster

The postlarva (larval stage IV) of the American lobster Homarus americanus is very different in form and behavior from earlier larval stages. Recruitment to the benthic population occurs during the postlarval period. Field observations in Rhode Island nearshore waters showed most postlarvae to be swimming in northerly to easterly directions. Average swimming speed in the field was 18 cm/s. Swimming speeds in the laboratory averaged 13.2 cm/s for field-captured and 10.7 cm/s for hatchery-reared postlarvae. Sustained directional swimming could have a considerable effect on postlarval distribution, and thus on patterns of recruitment to benthic populations.