Swimming Speed Research Articles

Accounting for interspecies and intraspecies variation in swimming performance for fish passage solutions

Abstract Across the globe, there are millions of in‐stream structures that fragment the world's river networks, acting as barriers that can impede the movements of fish. Designing effective solutions to accommodate fish communities requires information about the swimming abilities and behaviours of all species. This should account for different swimming modes, abilities, behaviours, and niches. We investigated the swimming speeds of nine migratory New Zealand species to assess both inter‐ and intraspecies variation. We then calculated maximum traversable speeds for culverts of a given length, based on the endurance abilities of our lowest performing species (Galaxias maculatus). Our findings reveal significant inter‐ and intraspecies variation in swimming speeds. Among the species studied, Galaxias brevipinnis, Galaxias argenteus, and Galaxias postvectis were the strongest swimmers. In contrast, Galaxias maculatus was one of the weakest swimmers. Body length positively correlated with Umax indicating that fish passage barriers select against the weakest swimming species, as well as smaller individuals within a species. Maximum water speeds in a culvert must be lower than 0.3 m s−1, the previously assumed standard rule‐of‐thumb for New Zealand, to provide adequate passage for a high proportion of a weak‐swimming indicator species (Galaxias maculatus). Synthesis and applications. Previous maximum traversable water speeds for fish passage designs have been based on average swimming ability, but this approach only enables fish that are better than the average swimmers of their species to overcome barriers. This study highlights the importance of evidence‐based designs for successful fish passage solutions to account for the ability of all fish. By considering differences between and within species, rather than assuming a ‘one‐size‐fits‐all’ approach we can develop more effective passage solutions that better preserve fish communities.

Tail length influences swimming speed of helical swimmers in granular media

Tail length influences swimming speed of helical swimmers in granular media

Hydrodynamic analysis of fish swimming behavior in turbulent river confluences

This study focuses on selecting the most appropriate turbulence model for simulating fish swimming behavior in river confluences. To achieve this, three numerical models—k-ε, k-ω, and large eddy simulation—were compared by running simulations under identical flow conditions and evaluating the results against biological experimental data. Among the models, the k-ω model demonstrated the smallest relative error, consistently within 5% of the experimental results, confirming its superior accuracy and reliability for this application. The k-ω model's ability to capture boundary layer turbulence and near-wall flow dynamics proved essential for studying fish swimming in complex turbulent environments. Simulations revealed that both the flow velocity ratio between the main stream and tributary and the confluence angle are critical factors influencing the flow structure. At higher flow velocity ratios (R = 1/3 and 3/1) or large confluence angles (α ≥ 90°), turbulence intensity increased, leading to more complex vortex formations that significantly impacted fish swimming speed. When the flow velocity ratio (R) is 1/3, the fish can achieve a maximum swimming speed of 2.75 L/s, which is significantly higher than the swimming speed of 1.18 L/s observed when R is 3/1. Additionally, fish closer to the center of the flow field experienced greater turbulence, resulting in higher energy expenditure. The findings provide crucial insights into the hydrodynamic mechanisms driving fish swimming behavior in dynamic aquatic environments.

Steady motions of single spherical microswimmers in non-Newtonian fluids

In biological systems, microswimmers often propel themselves through complex media. However, many aspects of swimming mechanisms in non-Newtonian fluids remain unclear. This study considers the propulsion of two types of single spherical microswimmers (squirmers) in shear-thickening and shear-thinning fluids. The slip-driven squirmer propels faster/slower in shear-thickening/thinning fluids than in Newtonian fluids [C. Datt et al., J. Fluid Mech. 784, R1 (2015)]. In contrast, we discovered that a traction-driven squirmer exhibits the opposite trend, moving slower/faster in shear-thickening/thinning fluids than in Newtonian fluids. In addition, we have shown theoretically that Purcell's scallop theorem does not hold in non-Newtonian fluids when a squirmer with reciprocal surface motions is used. The present findings open up possibilities for the design of new types of microswimmers that can achieve translational motion from a single reciprocal motion in non-Newtonian fluids. Furthermore, we demonstrated that traction-driven squirmers swim faster and more efficiently in shear-thinning fluids than in Newtonian fluids. These findings highlight how the non-Newtonian rheology enhances both swimming speed and efficiency, suggesting further potential for optimizing locomotion performance otherwise impossible in Newtonian fluids.

Increased Temperature and Exposure to Ammonium Alter the Life Cycle of an Anuran Species.

Amphibian populations are undergoing a major recession worldwide, likely triggered by global change components such as the global warming and pollutants, among which agrochemicals, in general, and fertilizers, in particular, play a central role given their relevance in agriculture. Potential synergies among these stressors could maximize their individual effects. In this work, we investigated the consequences of a controlled chronic exposure to increased temperature and a sublethal dose of ammonium during the larval stage of Pelophylax perezi frogs on the growth, development, and locomotor performance of tadpoles and the metamorphs they gave rise to. To that end, tadpoles were reared either in heated or nonheated tanks, with or without ammonium added. The parents of these tadpoles came from either a pine grove or an agrosystem. Survival was reduced in agrosystem tadpoles reared with ammonium. Increased temperature potentiated tadpole growth while giving way to smaller metamorphs. Faster growth could be a consequence of increased metabolism, whereas the smaller size could follow an accelerated development and metamorphosis, which reduced the growth period. Also, swimming speed was greater in tadpoles reared in heated tanks, while jumping distance was greater in metamorphs reared in nonheated tanks. The effects of temperature were more marked in agrosystem than in pine grove individuals, which could mirror reduced adaptability. Thus, the ability to withstand the effects of these stressors was lower in agrosystem tadpoles.

Genetic basis analysis and genome prediction of swimming performance traits in juvenile spotted sea bass (Lateolabrax maculatus)

The swimming performance of fish is crucial for their survival, playing a significant role in enhancing disease resistance and facilitating stress recovery, particularly in aquaculture fish. Understanding the genetic basis of fish swimming performance is essential for its integration as a key trait in selection breeding programs, especially for deeper offshore aquaculture. Spotted sea bass, an economically important aquaculture fish species in China, exhibits euryhaline and eurythermic characteristics and has demonstrated substantial potential for deep-sea aquaculture. Therefore, in our study, the absolute critical swimming speed (a.Ucrit) of juvenile spotted sea bass were assessed, ranging form 24.50 cm s−1 to 65.00 cm s−1, and this range enabled the identification of individuals with superior and inferior swimming abilities within the test population. Based on whole-genome resequencing, genome-wide association studies (GWAS) were conducted for three phenotypes of swimming performance, identifying 25 associated SNPs and 85 candidate genes, indicating that it is a polygenetic trait influenced by multiple biological processes. The heritability estimates for a.Ucrit and relative critical swimming speed (r.Ucrit) were 0.21 ± 0.08 and 0.22 ± 0.08, respectively. Furthermore, the impact of various genomic selection (GS) models and SNP densities on prediction accuracy of swimming performance was evaluated using genomic prediction (GP). The SVM model is recommended for continuous trait prediction of swimming performance, especially when SNP densities ranges between 500 and 50 K, as it provides more accurate, efficient and stable predictions. Our research further enhances the understanding of the genetic basis of fish swimming performance and holds promise for improving productivity in deep-sea aquaculture through genomic selection.

Assessment of humpback whale swimming speeds in two eastern Australian bays

Assessment of humpback whale swimming speeds in two eastern Australian bays

Effects of maximum thickness position on hydrodynamic performance for fish-like swimmers

When designing the internals of robotic fish, variations in the internal arrangements of power and control systems cause differences in external morphological structures, particularly the positions of maximum thickness. These differences considerably affect swimming performance. This study examines the impact of the topological structure of self-propelled fish-like swimmers on hydrodynamic performance using fluid-structure interaction techniques. Fish-like swimmers with maximum thickness closest to the head exhibit optimal swimming performance, characterized by modest energy consumption for fast-response acceleration during the starting phase and higher swimming velocity for high-speed travel during steady swimming. As the maximum thickness moves toward the middle, acceleration performance significantly weakens and swimming speed decreases, although maximum energy consumption is relatively reduced. This study will provide a notable reference for the morphological design of underwater robotic fish.

The effects of warm thermal variability on metabolism and swimming performance in wild Atlantic salmon (Salmo salar).

Warmer and more variable temperatures have been implicated in the recent decline of Atlantic salmon (Salmo salar) in Eastern Canada. To date, we know little on how ecologically relevant thermal fluctuations affect swimming performance in fishes. The goal of this study is to determine the effects of warm versus cool diel thermal variability on swimming efficiency and the speed limit for sustainable aerobically fueled swimming. We acclimated wild S. salar juveniles to a cool and a warm ecologically realistic diel thermal profile (16-21 and 19-24°C), and then tested individuals over a common acute change in temperature (16-24°C). We measured metabolic rate and swimming kinematics at a range of swimming speeds, at five temperatures (16, 18, 20, 22, and 24°C) and calculated swimming efficiency. Our temperature acclimation did not appear to significantly affect energetic and kinematic swimming efficiency, but acute exposure to high temperature did increase overall metabolic rate. It appears that wild S. salar can swim efficiently and sustainably during both acute cool and warm exposures, and after acclimation to diel thermal variation of 16-21 or 19-24°C.

Swimming kinematics of deep-sea fishes.

Although the deep oceans represent Earth's largest habitat, the challenges of studying deep-sea organisms in situ have limited our understanding of adaptation, ecology, and behaviour in these important ecosystems. One fundamental trait of fishes that remains largely unexplored in the deep ocean is swimming, a vital process for movement, migration, and dispersal in marine habitats. Deep-sea conditions such as temperature, pressure, and food availability could each impact the speed and efficiency of swimming in fishes. To investigate swimming kinematics of fishes with increasing depth, we analysed in situ video of bony fishes across a 6000-m depth gradient. We compared open-source videos of fishes from National Oceanic and Atmospheric Administration (NOAA)Ocean Exploration with tank-based recordings of shallow-water relatives from Puget Sound, Washington, USA to understand how both habitat depth and phylogeny influence swimming in fishes. We analysed kinematics in four dominant demersal fish groups, the orders Anguilliformes, Gadiformes, Ophidiiformes, and Perciformes. Deep-sea fishes swam consistently slowly. Swimming kinematics varied across temperature, oxygen, body elongation, and depth. These results suggest that swimming kinematics do not change linearly with increasing habitat depth in fishes and that the impacts of deep-sea conditions such as low temperatures, high pressures, and low nutrient availability on swimming behaviour need to be considered independently of one another. These findings provide insight into the evolution of fish form and function in the deep ocean.

Near-maximally swimming schoolmaster snapper (Lutjanus apodus) have a greater metabolic capacity, and slightly lower thermal tolerance, than when tested at rest.

To assess the relationship among various measures of thermal tolerance and performance suggested for use in fish, we determined the critical thermal maximum (CTmax), critical swimming speed (Ucrit), maximum thermal tolerance while swimming [CTSmax] and realistic aerobic scope (ASR) of juvenile schoolmaster snapper (Lutjanus apodus). Their CTSmax (37.5±0.1°C) was only slightly lower than their CTmax (38.9±0.1°C) and this is probably because their maximum metabolic rate (MMR) and ASR during the former test were ∼42 and 65% higher, respectively. Furthermore, we did not observe a transition to unsteady (i.e. anaerobically fueled) swimming in the CTSmax test as we did in the Ucrit protocol. These data strongly suggest that thermal tolerance tests on fishes whose lifestyle involves schooling or sustained activity should be performed at ecologically relevant swimming speeds. Our results do not support the hypothesis that failure during a CTSmax test is due to a fish's inability to meet its tissue oxygen demands.

Endurance of leg muscle strength and endurance of arm muscle strength to the ability of swimming speed 200 meters breaststroke

The lack of breaststroke swimming ability among athletes has led to a decline in breaststroke swimming performance in the Solok city swimming association. This problem is thought to be related to the low endurance of leg and arm muscles to the swimming speed of 200 meters breaststroke. This correlational study aims to reveal the contribution of leg muscle endurance, arm muscles, and the joint contribution of both to swimming speed 200 meters breaststroke in athletes coaching achievements in the Solok city swimming association. This study involved 25 swimming athletes in Solok city, with total sampling technique. Data on leg muscle strength endurance was measured through the squat jump test, arm muscle strength endurance through the push up test, and swimming speed through the 200 meter breaststroke swimming test. Data were analyzed using simple and multiple correlations with a significant level of α = 0.05, and the contribution was calculated by the formula r² x 100%. The results of data analysis showed that leg muscle strength endurance contributed 74.65%, while arm muscle strength endurance contributed 70.06%. The combination of both contributed 74.99% to the ability of 200 meters breaststroke swimming speed of athletes coaching achievements in swimming associations in Solok city.

Devouring Atherosclerotic Plaques: The Engineered Nanorobot Rousing Macrophage Efferocytosis by a Two‐Pronged Strategy

AbstractInvestigating the potential of macrophage efferocytosis has led to a growing interest in exploiting macrophage in immunotherapy. Macrophage‐specific nano‐medicines are currently being developed to stimulate the phagocytic clearance of apoptotic debris in atherosclerosis; however, these unnatural nanoparticles exhibit poor biocompatibility and limited efferocytosis activation ability. Here a pro‐efferocytosis biomimetic nanorobot UM‐EVLipo is developed based on nano‐motor and extracellular vesicles (EVs) hybridized with plaque double‐targeted liposomes. An elegant procedure with only 4 steps is integrated to prepare and purify these hybrid nanovesicles. It is first demonstrated that the EVs derived from bone marrow macrophages stimulated with IL‐4 can promote the transformation of M0 and M1 macrophages into M2, an efferocytosis phenotype. Furthermore, the EVs hybridized with SHP‐1 siRNA‐liposomes blocked the “don't eat me” signal from apoptotic debris by intervening CD47‐SIRPα‐SHP‐1 axis. This two‐pronged strategy of resetting phenotype and blocking checkpoints furthest activates macrophage efferocytosis. Importantly, the urease motor increased the swimming speed of nanovesicles in the blood by 12.4 times, making it easier for them to penetrate the endothelial barrier. The UM‐EVLipo accumulated within the atherosclerotic plaque, reactivate lesioned efferocytosis and reduce the plaque area in the carotid and coronary, which demonstrates the potential of a two‐pronged strategy to prevent atherosclerotic cardiovascular disease.

Novel nerve regeneration assessment method using adult zebrafish with crush spinal cord injury.

Zebrafish (Danio rerio), an alternative to rodents, are widely used in neurological, genetic, and toxicology research. The zebrafish larval spinal cord injury model has been used in neural mechanistic analyses owing to its high regenerative capacity and throughput; however, it also had several limitations in imitating rodents. Therefore, we investigated the use of adult zebrafish as an alternative model to rodents for evaluating nerve regeneration. Here, we established a novel spinal cord regeneration evaluation method, which was based on the maximum swimming speed of adult zebrafish in a custom-built hydrodynamic-based aquarium. The spinal cords of adult male zebrafish were crushed using forceps, and maximum swimming speed and histological spinal cord regeneration were evaluated. Spinal cord-injured zebrafish showed a significant decline in motor function, followed by recovery at 3weeks postoperatively, accompanied by histological regeneration. Spinal cord regeneration can be indirectly assessed by monitoring maximum swimming speed. They were also fed a diet containing fig extract, which can promote peripheral nerve regeneration; they were fed daily starting 1week before the operation. Maximum swimming speed was measured time-dependently until 3weeks postoperatively. Fig-consuming fish showed improved recovery of maximum swimming speed compared to the controls, which was consistent with the histological analysis. In summary, we established a spinal cord regeneration assessment system using adult zebrafish in a customized aquarium, which enables researchers to evaluate spinal cord regeneration in adult zebrafish similar to that of rodent experiments, contributing to faster and easier screening of neuroregenerative technology.

The Relatioship between Leg Muscle Strength Arm Muscles and Self-Confidence with 50 Metres Swimming Speed Free Style

The purpose of this study was to determine the relationship between leg muscle strength and self-confidence, arm muscle strength and self-confidence, and leg muscle strength, arm muscle strength and self-confidence with 50-meter freestyle swimming speed. The sample of this study was 30 male students. In accordance with the formulation of the problem and the objectives to be achieved, the research method used in this study is a quantitative method with correlation and descriptive techniques, namely the researcher will see the relationship between one variable and another. Based on the results of the analysis of research data and discussion, it can be concluded that the following research results (a) there is a relationship between leg muscle strength and 50-meter freestyle swimming speed of 3.61 (b) there is a relationship between arm muscle strength and 50-meter freestyle swimming speed of 3.47. (c) there is a relationship between self-confidence and 50-meter freestyle swimming speed of 4.95 which then the relationship between leg muscle strength and arm muscle strength and self-confidence with 50-meter freestyle swimming speed of 14.99. Thus, the stronger the leg and arm muscles, as well as good self-confidence, the better the 50-meter freestyle swimming speed of male students of the Health and Sports Study Program, FKIP Unpatti Ambon. Keywords: Swimming 50 meters freestyle, leg muscle strength, arm muscle, self-confidence

Supramammillary Theta Oscillations in Water Maze Learning.

The supramammillary nucleus (SuM) in the hypothalamus, in conjunction with the hippocampus (HPC), has been implicated through theta oscillations in various brain functions ranging from locomotion to learning and memory. While the indispensable role of the SuM in HPC theta generation in anesthetized animals is well-characterized, the SuM is not always necessary for HPC theta in awake animals. This raises questions on the precise behavioral relevance of SuM theta activity and its interaction with HPC theta activity. We used simultaneously recorded SuM and HPC local field potentials (LFPs) in a one-day water maze (WM) learning paradigm in rats (n = 8), to show that theta activities recorded from the SuM itself were not positively correlated with locomotor (swimming) speed nor acceleration, but the individual relationship between acceleration and SuM theta frequency is correlated with WM learning rates. In contrast, we found that SuM-HPC theta phase coherence is strongly correlated with swimming speed and acceleration, but these do not relate to WM learning. SuM-HPC-directed coherence analysis demonstrated no swimming kinetics nor learning rate associations, but revealed that periods of high SuM-HPC theta phase coherence are driven by the SuM at relatively low (~6.2 Hz) frequencies. Additionally, we demonstrate that the SuM and the HPC also engage in non-random, non-coherent phase coupling modes where either structure preferentially displays a ± 2 Hz difference with the other. Our data indicate SuM theta LFPs do not appear to be related to either speed coding or spatial learning in swimming rats and display non-random out-of-phase theta frequency coupling with the HPC.

Optimizing light environments in aquatics center to enhance the performance of Olympic champions and other elite swimmers: An experimental study

Several major international sports events in the next five years require new sports venues, with lighting environments being a crucial factor. Typically, the lighting systems in sports venues are primarily for illumination. However, since light has been indicated to affect human psychology and physiology, we investigated whether the light environments in sports buildings impact athletic performance. Additionally, swimming is the indoor sport with the most gold medals in the Olympics. Therefore, we conducted a within-subject, randomized crossover study in an aquatics center with fourteen elite swimmers, including the Olympic champions and Asian champions (6 female and 8 male; 19.3 ± 3.4 years of age). During the experiment, the elite swimmers were exposed to either a common correlated color temperature (CCT) light environment (controlled condition: 5780 K) or an experimental light environment (8512 K) in the aquatics center, with both having the same illuminance (1020 lx). The neurobehavioral and swimming test results showed that the Olympic champions and other elite swimmers had significantly faster responses, fewer lapses, greater arousal, less visual fatigue, quicker reactions at start, and higher swimming speeds in the experimental condition compared to the controlled condition (p < 0.05). Our findings suggest that the light environment in the aquatics center affects swimmers' non-visual performance and enhancing the CCT of the light environment could improve swimmers' performance. We propose the concepts of Sports Lighting Beyond Illumination and Sports Human-Centric Lighting to enhance athletes’ health and performance, and to improve the sports environment for a better experience for all participants.

Quantifying and reducing the cost of tagging: combining computational fluid dynamics and diving experiments to reduce impact from animal-borne tags.

Animal-borne instruments are essential research tools for ecologists and physiologists. An increasing number of studies have shown impacts of carrying a tag on behaviour and energetics, which can have implications for animal welfare and data validity. Such impacts are a result of the additional mass and/or drag loads, with the latter requiring empirical measurements or computational fluid dynamics (CFD) to estimate. To quantify and effectively minimize tag impacts from drag, a novel combined empirical and CFD approach is required. Here, we demonstrate such an approach using captive phocid seals and the widely used Sea Mammal Research Unit (SMRU) Instrumentation Group GPS/GSM tag. We (i) show a significant change in the behaviour of grey seals when carrying a tag (gen 1; associated with 16.4% additional drag); (ii) redesigned the tag (gen 2) resulting in a lower additional drag of 8.6%; (iii) show significant differences in behaviour when carrying a gen 2 compared to gen 1 tag, demonstrating that the redesign successfully reduced impact; and (iv) observed changes in the swim speed of seals that were consistent with predictions from CFD estimates of drag. The gen 2 instrument is now commercially available. This non-trivial case study should pave the way for similar studies in other taxa and species.

Early rearing of European seabass (Dicentrarchus labrax) with mild current enrichment modifies fish swimming behavior without altering their growth performance

The implementation of conditions that favor optimum swimming activity (e.g., suitable flow regimes), has been associated with enhanced growth and improved welfare in some farmed fish species. Despite the importance of European seabass in aquaculture, the potential beneficial effects of rearing flow conditions have not been sufficiently explored in this species. This study investigates how the application of fast (F, 0.01–0.20 m s-1) or slow (S, <0.01 m s-1) steady flows in rearing tanks for 75-77 days affected physiological and behavioral traits in seabass fingerlings. Growth performance, external and internal morphology, and several physiological variables, including hematocrit, plasma cortisol concentration, and osmotic and ionic balance were not affected by flow conditions during rearing. Also, behavioral tests implemented in groups or isolated individuals suggest that coping styles were not affected by the two tank-rearing conditions. On the contrary, the swimming behavior assessed in tests was modified by the flow condition experienced during rearing. Mean swimming speed, peak acceleration, swimming distance, angular velocity, and meander showed some variability across different tests and time, although consistently displaying higher values in seabass reared in the F condition, suggesting increased activity and more consistent swimming patterns in that group. However, the cumulative time in proximity between individuals measured in behavioral group tests suggested that group cohesion was variable, without displaying differences between F and S groups. These findings have particularly important implications for fish welfare and may suggest plasticity in the behavioral response to rearing conditions for this species, although not affecting the assignment of the individuals to the different coping styles. Summary statementWe investigated how mild current enrichment applied during early rearing in seabass modifies physiological and behavioral responses involving swimming activity, exploring the potential associations to fish welfare.

The calculated voyage: benchmarking optimal strategies and consumptions in the Japanese eel’s spawning migration

Eels migrate along largely unknown routes to their spawning ground. By coupling Zermelo’s navigation solution and data from the Japan Coastal Ocean Predictability Experiment 2 (JCOPE2M), we simulated a range of seasonal scenarios, swimming speeds, and swimming depths to predict paths that minimize migration duration and energy cost. Our simulations predict a trade-off between migration duration and energy cost. Given that eels do not refuel during their migration, our simulations suggest eels should travel at speeds of 0.4–0.6 body-length per second to retain enough energy reserves for reproduction. For real eels without full information of the ocean currents, they cannot optimize their migration in strong surface currents, thus when swimming at slow swimming speeds, they should swim at depths of 200 m or greater. Eels swimming near the surface are also influenced by seasonal factors, however, migrating at greater depths mitigates these effects. While greater depths present more favorable flow conditions, water temperature may become increasingly unfavorable, dropping near or below 5 °C. Our results serve as a benchmark, demonstrating the complex interplay between swimming speed, depth, seasonal factors, migration time, and energy consumption, to comprehend the migratory behaviors of Japanese eels and other migratory fish.