Burst Swimming Performance Research Articles

Stenotherms at sub-zero temperatures: thermal dependence of swimming performance in Antarctic fish.

We examined the burst swimming performance of two Antarctic fishes, Trematomus bernacchii and T. centronotus, at five temperatures between -1 degrees C and 10 degrees C. As Antarctic fishes are considered one of the most cold specialised and stenothermal of all ectotherms, we predicted they would possess a narrow thermal performance breadth for burst swimming and a correlative decrease in performance at high temperatures. Burst swimming was assessed by videotaping swimming sequences with a 50-Hz video camera and analysing the sequences frame-by-frame to determine maximum velocity, the distance moved throughout the initial 200 ms, and the time taken to reach maximum velocity. In contrast to our prediction, we found both species possessed a wide thermal performance breadth for burst swimming. Although maximum swimming velocity for both T. bernacchii and T. centronotus was significantly highest at 6 degrees C, maximum velocity at all other test temperatures was less than 20% lower. Thus, it appears that specialisation to a highly stable and cold environment is not necessarily associated with a narrow thermal performance breadth for burst swimming in Antarctic fish. We also examined the ability of the Antarctic fish Pagothenia borchgrevinki to acclimate their burst-swimming performance to different temperatures. We exposed P. borchgrevinki to either -1 degrees C or 4 degrees C for 4 weeks and tested their burst-swimming performance at four temperatures between -1 degrees C and 10 degrees C. Burst-swimming performance of Pagothenia borchgrevinki was unaffected by exposure to either -1 degrees C or 4 degrees C for 4 weeks. Maximum swimming velocity of both acclimation groups was thermally independent over the total temperature range of 1 degrees C to 10 degrees C. Therefore, the loss of any capacity to restructure the phenotype and an inability to thermally acclimate swimming performance appears to be associated with inhabiting a highly stable thermal environment.

Allometric scaling of maximal enzyme activities in the axial musculature of striped bass, Morone saxatilis (Walbaum).

It had been suggested that the activity of anaerobic enzymes in the white muscle of fish increases exponentially with body size to meet the increasing hydrodynamic costs of burst swimming. We tested whether this relationship holds across a very large size range of striped bass, spanning a nearly 3,000-fold range in body mass. We examined the scaling of marker enzymes of anaerobic (lactate dehydrogenase and pyruvate kinase) and aerobic (citrate synthase and malate dehydrogenase) metabolism in the red and white locomotor muscles. In white muscle, we found positive scaling of anaerobic enzymes only in smaller fishes. Positive scaling of anaerobic enzymes was not found among the samples that included fishes >1,000 g despite having a sufficiently large sample size to detect such scaling. The absence of positive scaling in the white muscles of large bass suggests that they are unable to generate sufficient power to sustain relative burst swimming performance. Enzymes from aerobic pathways had activities that were mass independent in both red and white muscle. Red and white muscles were metabolically distinct except among the smallest fishes. Among young of the year, the anaerobic capacity of red muscle approached that of white muscle and also showed positive scaling. This unusual pattern suggests that red muscle might augment white muscle during burst swimming and add to the total power generated by these small fish. Maximizing burst swimming performance may be critical for small fishes vulnerable to predation but unimportant for large fishes.

Effect of ontogenetic increases in body size on burst swimming performance in tadpoles of the striped marsh frog, Limnodynastes peronii.

The effect of ontogenetic increases in total length on burst swimming performance was investigated in tadpoles of the striped marsh frog (Limnodynastes peronii) over the total-length range of 1. 5-4 cm and Gosner developmental stages 25-38. The burst swimming performance of tadpoles at 10 degrees and 24 degrees C was determined by videotaping startle responses with a high-speed video camera at 200 Hz and analysing the sequences frame by frame. Maximum swimming velocity (Umax) and acceleration (Amax) increased with total length (L) at a rate that was proportionally greater than the increase in total length (i.e., positive allometry; exponents >1) and was described by the allometric equations Umax=0.061L1.34 and Amax=1.15L1.11 at 10 degrees C and Umax=0.114L1.34 and Amax=1.54L1. 11 at 24 degrees C. Stride length increased with a total-length exponent of approximately 1 but was unaffected by temperature. Tail-beat frequency was not affected by total length and increased from 7.8+/-0.2 Hz at 10 degrees C to 21.7+/-0.7 Hz at 24 degrees C. Developmental stage did not significantly influence the relationship between total length and Umax or Amax. Furthermore, temperature and the associated changes in water viscosity did not affect the relationship between total length and burst swimming performance. At their Umax, Reynolds numbers ranged from approximately 1,500 in the smaller tadpoles up to 50,000 for the larger animals at 24 degrees C. We suggest the positive allometry of Umax in larval L. peronii was due in part to the increases in tail width (TW) with total length (TW=-1.36L1.66), possibly reflecting the increasing importance of burst swimming performance to survival during larval development.

Thermal acclimation of locomotor performance in tadpoles of the frog Limnodynastes peronii.

Previous analyses of thermal acclimation of locomotor performance in amphibians have only examined the adult life history stage and indicate that the locomotor system is unable to undergo acclimatory changes to temperature. In this study, we examined the ability of tadpoles of the striped marsh frog (Limnodynastes peronii) to acclimate their locomotor system by exposing them to either 10 degrees C or 24 degrees C for 6 weeks and testing their burst swimming performance at 10, 24, and 34 degrees C. At the test temperature of 10 degrees C, maximum velocity (Umax) of the 10 degrees C-acclimated tadpoles was 47% greater and maximum acceleration (Amax) 53% greater than the 24 degrees C-acclimated animals. At 24 degrees C, Umax was 16% greater in the 10 degrees C-acclimation group, while there was no significant difference in Amax or the time taken to reach Umax (T-Umax). At 34 degrees C, there was no difference between the acclimation groups in either Umax or Amax, however T-Umax was 36% faster in the 24 degrees C-acclimation group. This is the first study to report an amphibian (larva or adult) possessing the capacity to compensate for cool temperatures by thermal acclimation of locomotor performance. To determine whether acclimation period affected the magnitude of the acclimatory response, we also acclimated tadpoles of L. peronii to 10 degrees C for 8 months and compared their swimming performance with tadpoles acclimated to 10 degrees C for 6 weeks. At the test temperatures of 24 degrees C and 34 degrees C, Umax and Amax were significantly slower in the tadpoles acclimated to 10 degrees C for 8 months. At 10 degrees C, T-Umax was 40% faster in the 8-month group, while there were no differences in either Umax or Amax. Although locomotor performance was enhanced at 10 degrees C by a longer acclimation period, this was at the expense of performance at higher temperatures.

Metabolic correlates of burst swimming capacity of juvenile and adult threespine stickleback ( Gasterosteus aculeatus )

The relationship between burst swimming performance and muscle metabolic capacities was examined in juvenile and adult threespine sticklebacks (Gasterosteus aculeatus). The absolute burst speed measured during startle responses increased markedly with growth of juveniles, but this positive allometry did not continue in adults. The allometry of phosphofructokinase (PFK), lactate dehydrogenase, creatine phosphokinase activities and protein concentrations was positive in juveniles and became negative in adults. The lower activities in adults may reflect the mobilization of muscle proteins for reproduction. In juveniles, absolute burst swimming and muscle glycolytic capacity show a similar allometry. However, when the influence of factors such as size and age was removed by calculating residuals from multiple regressions, variation in muscle enzyme activities in juveniles did not explain variation in their swimming capacity. In adults, interindividual variation in PFK and cytochrome C oxidase activities was correlated with variation in the burst swimming capacity. Apparently, mobilization of muscle proteins in support of reproduction may lead muscle enzyme levels to limit burst performance.

Studies of evolutionary temperature adaptation: muscle function and locomotor performance in Antarctic fish.

1. Studies of evolutionary temperature adaptation of muscle and locomotor performance in fish are reviewed with a focus on the Antarctic fauna living at subzero temperatures. 2. Only limited data are available to compare the sustained and burst swimming kinematics and performance of Antarctic, temperate and tropical species. Available data indicate that low temperatures limit maximum swimming performance and this is especially evident in fish larvae. 3. In a recent study, muscle performance in the Antarctic rock cod Notothenia coriiceps at 0 degree C was found to be sufficient to produce maximum velocities during burst swimming that were similar to those seen in the sculpin Myoxocephalus scorpius at 10 degrees C, indicating temperature compensation of muscle and locomotor performance in the Antarctic fish. However, at 15 degrees C, sculpin produce maximum swimming velocities greater than N. coriiceps at 0 degree C. 4. It is recommended that strict hypothesis-driven investigations using ecologically relevant measures of performance are undertaken to study temperature adaptation in Antarctic fish. Recent detailed phylogenetic analyses of the Antarctic fish fauna and their temperate relatives will allow a stronger experimental approach by helping to separate what is due to adaptation to the cold and what is due to phylogeny alone.

Burst swimming and its enzymatic correlates in the threespine stickleback (Gasterosteus aculeatus): full-sib heritabilities

Full-sib heritabilities of burst-swimming capacity and its enzymatic correlates were calculated in juvenile threespine sticklebacks, Gasterosteus aculeatus, from 25 families raised under constant laboratory conditions. Variation among families in burst-swimming performance, enzyme activities, body size, and condition of the juveniles was considerable. Estimates of full-sib heritabilities of absolute and relative burst-swimming performance decreased during ontogenesis, as they were higher for 2-month-old than for 3.6-month-old sticklebacks. This decline may reflect a decrease in the importance of paternal effects with age, as well as an increase in intrafamilial variability due to the existence of feeding or social hierarachies. Enzymatic correlates of burst-swimming performance measured in 3.6-month-old sticklebacks had higher full-sib heritabilities than burst-swimming performance itself, with the highest values found for cytochrome c oxidase, followed by lactate dehydrogenase and then phosphofructokinase and creatine phosphokinase. These results suggest that genetic factors may have a considerable influence upon burst-swimming performance and muscle metabolic capacities of juvenile threespine sticklebacks, but that this influence may be tempered by biotic interactions.

Measurement of burst swimming performance in wild Atlantic salmon (Salmo salar L.) using digital telemetry

Swimming performance of wild Atlantic salmon (Salmo salar L.) was investigated in an experimental flume using coded radio signals. To calculate swimming speed, distance moved and time elapsed were measured with a digital spectrum processor using near real-time spectrum analysis. This device was designed to be used in a coprocessing arrangement with a receiver, thereby providing pulse position code discrimination, verification and continuous data storage. Radio-tagged adults (48.3 to 54.8 cm long) voluntarily swam against water velocities, ranging from 1.32 to 2.85 m s−1, in an 18 m long flume at a mean water temperature of 10.1±1.6°C. At water velocities of 1.32–1.55 m s−1, individuals successfully ascended the flume at swimming speeds of 1.61–2.55 m s−1, or 3.30–4.79 body lengths per second (l s−1), respectively. At high water velocities ranging from 1.92 to 2.85 m s−1, individual swimming speeds increased from 2.55 to 3.60 m s−1, or 4.94–7.27 l s−1, respectively. However, above a threshold value of 1.92 m s−1, individuals traversed shorter distances and were unable to ascend the flume. The highest swimming speed observed was 4.13 m s−1, or 8.35 l s−1. The results of this study indicate that in addition to its applicability in the determination of burst swimming speeds, digital telemetry could prove a useful tool in the design and evaluation of future fishways and culvert installations. © 1998 John Wiley & Sons, Ltd.

Predator-Mediated Selection on Burst Swimming Performance in Tadpoles of the Pacific Tree Frog, Pseudacris regilla

Two experimental approaches were used to determine if burst swimming speed in Pseudacris regilla tadpoles is subject to selection by predatory garter snakes, Thamnophis sirtalis. In eight out of 10 experiments in seminatural arenas, fast tadpoles survived snake predation more often than expected (P < 0.01). In videotaped encounters, tadpoles that escaped attacks swam 1.68 times as fast (P < 0.0001) and nearly four times as evasively (P < 0. 05) as those that were captured. Burst swimming speed is clearly important to success at escaping snakes in experimental arenas and, given widespread snake predation on tadpoles, is probably subject to predator-mediated selection in nature.

Thermal effects

Thermal effects

The Effect of Temperature on the Burst Swimming Performance of Fish Larvae

ABSTRACT Newly hatched herring and plaice larvae were stimulated by probes to make C-start escape responses at temperatures between 5 and 15°C. The responses and the subsequent burst-speed swimming were recorded and analysed using highspeed video at 400 frames s−1. The muscle contraction time of the initial C-start was temperature-dependent, ranging from 22–33 ms at 5°C to 17–21 ms at 15°C. Immediately following the C-start, tail-beat frequency ranged from 18s−1 at 5°C to 35 s−1 at 15°C. Tail-beat amplitude, equivalent to 0.4–0.6 of a body length (L), and stride length, about 0.5 L, were not temperature-dependent. The escape speed ranged from 8Ls−1 at 5°C to 15 Ls−1 at 15°C. These results and those of other workers can be described by the equation: where f is tail-beat frequency, t is temperature and L is length.

THE FUNCTIONAL BASIS OF NATURAL SELECTION FOR VERTEBRAL TRAITS OF LARVAE IN THE STICKLEBACK GASTEROSTEUS ACULEATUS.

Previous studies have demonstrated selective predation for vertebral traits of larvae in the stickleback Gasterosteus aculeatus. I tested the hypothesis that this selection results from a direct functional advantage to particular vertebral phenotypes by direct measurement of the burst swimming performance of larvae. Within a narrow window of lengths, burst speed did depend on vertebral phenotype. As in the previous predation experiments, performance was related more directly to the ratio of abdominal to caudal vertebrae (VR) than to the total number of vertebrae (VN), and the optimal VR decreased as larval length increased. Changes with length in the vertebral phenotype frequencies of wild larvae provided evidence of selection for VR and for VN in the wild. Larvae with particular VR increased in frequency in the wild at just those lengths when their relative performance was superior in the laboratory. The observed pattern of length-dependent selection for vertebral number provides an explanation for the widespread trends in vertebral number that occur among populations of related fishes.

The Scaling of Aerobic and Anaerobic Muscle Power in Rainbow Trout(Salmo Gairdneri)

ABSTRACTThe scaling of anaerobic metabolism and red muscle mass was examined in rainbow trout (Salmo gairdneri) ranging in size from 2 to 1200 g. The initial rate of white muscle lactate production during maximal burst activity was significantly higher in large (28·lcm) than in small (8·0cm) fish. ‘Resting’ lactate concentrations in anesthetized trout (approximately 30 s of stress) increased with fish size, also reflecting higher glycolytic potential for larger fish. Maximum muscle lactate concentrations following 6 min of exhaustive exercise increased from approximately 25 to 45 μmolg−1 with increased fish size (= L0·36, where L is fish length). Total white muscle lactate production, including changes in muscle mass, scaled as L3·52. A scaling comparison of total anaerobic capacity with theoretically predicted power requirements indicated decreased burst swimming performance with increased size. Red muscle mass increased from approximately 1 to 3 % of body mass with increased fish size. The positive allometry in red muscle mass (= L3·62) is greater than the scaling of power requirements during aerobic swimming predicted from hydrodynamic theory, and may provide compensation for decreased mass-specific power output with increased size.

Burst-Swimming Performance of Larval Zebra Danios and the Effects of Diel Temperature Fluctuations

Zebra danios Danio [Brachydanio] rerio were spawned and their eggs and larvae were reared in a simulated natural thermal regime, increasing from 21 to 30°C for 7 h and decreasing to 21°C for 17 h, daily. Burst-swimming performance was provoked by electrical stimulation of larvae (mean total length = 3.6 mm). Responses were filmed at 400 frames/s at temperature intervals of 3°C. Distance travelled in a specified time (St), maximum velocity, and maximum acceleration increased with temperature. Size-specific maximum velocity was considerably higher than previously reported for larvae. A predictive model relating St to temperature was developed. In theory, the observed effects of temperature could have been due to changes in physiological rates or in water viscosity, but Reynolds numbers were too high for a substantial viscosity effect. The Q10 for St was 1.6, that for maximum velocity was 1.4. Results suggest that, other factors being equal, larvae are potentially more vulnerable to predation at sunrise or at other times when water temperature is low.

Burst Swimming and Size-Related Predation of Newly Emerged Coho Salmon Oncorhynchus kisutch

Abstract Burst swimming by newly emerged coho salmon from two populations was studied with electrical shock stimulation and high-speed cinematography. At emergence, Morrison Creek fish were larger (31 versus 27 mm standard length) than fish from Wade Creek. The larger fish attained greater mean and maximum burst speeds than the smaller fish and differences in swimming performance (up to 80%) were greatest over the first 0.03 s of acceleration. When exposed to 140-mm coho salmon predators, more of the larger Morrison Creek fish survived than of the Wade Creek fish. Size-mediated differences in burst swimming performance appear to be the basis for the observed difference in susceptibility to predation.

A Violation of the Metabolism-Size Scaling Paradigm: Activities of Glycolytic Enzymes in Muscle Increase in Larger-Size Fish

The activities (units per gram wet weight of tissue) of two glycolytic enzymes (lactate dehydrogenase [LDH] and pyruvate kinase [PK]) and two citric acid cycle enzymes (citrate synthase [CS] and malate dehydrogenase [MDH]) were measured in epaxial white muscle of different-sized specimens of 13 teleost species. For CS, an enzyme associated with aerobic metabolism, the units of activity per gram muscle decreased with increasing body size, following the scaling pattern characteristically observed for aerobic respiration as a function of body size. The two anaerobically poised enzymes, LDH and PK, exhibited significantly higher activity per gram muscle in larger specimens. The dramatic increases in LDH and PK activities, both in terms of units per gram muscle and units of muscle activity per gram of total fish mass, were analyzed from the standpoint of power requirements for burst-swimming performance, since glycolytic capacity may determine a fish's ability to swim at high relative (body lengths per second) velocities. The scaling of muscle power required for maintenance of identical burst-swimming abilities (in body lengths per second) in large and small individuals of a species, based on calculations of drag scaling with body size and relative swimming velocity, agrees closely with the observed scaling of LDH and PK activity in white epaxial muscle. Brain enzymic activities were examined in three species to determine whether enzyme scaling with body size also occurred in a nonlocomotory tissue. The LDH and PK activities were virtually constant over a wide range of body size in all three species; CS activity exhibited a scaling with body size similar to the relationship found for white muscle CS activity and similar to the relationship expected between respiratory rate and body size. These different enzymic activity scaling patterns for aerobically and anaerobically poised enzymes are discussed in terms of the body-sizedependent aerobic. swimming abilities and body-size-independent anaerobic (burst) swimming abilities of fish. The ecological significance of maintaining size-independent burst-swimming ability, as measured in body lengths per second, is also considered. The contrasting aerobic and anaerobic enzyme scaling patterns found in this study indicate that the metabolic scaling paradigm observed in numerous studies of respiratory metabolism may not be applicable to anaerobic metabolism since different constraints on metabolic rate may apply under aerobic and anaerobic conditions. Limitations on aerobic metabolism may derive from surface-volume relationships and on oxygen transport capacities, i.e., on intertissue relationships. In contrast, limitations on short-term anaerobic metabolism, as used in burst swimming, may involve only intratissue factors, notably glycogen concentration and the activities of glycolytic enzymes like PK and LDH that are instrumental in supplying ATP and in regenerating NAD⁺.