Slow Swimming Research Articles

Identification, genome-wide sequencing and analysis of drug resistance genes in a novel Vibrio harveyi strain isolated from yellowfin seabream

Yellowfin seabream (Acanthopagrus latus) is a fast-growing, adaptable species crucial for fish farming in southern China. However, as aquaculture of this species expands, diseases caused by bacteria, particularly Vibrio harveyi, are causing substantial economic losses. In this study, we isolated and identified a Vibrio harveyi strain denoted VH-AQ-SCAU-GZ23 from the diseased fish. Clinical signs of VH-AQ-SCAU-GZ23 infection were slow swimming, loss of appetite, loss of scales, severe liver congestion, and swelling of the gill filaments. VH-AQ-SCAU-GZ23 also induced an inflammatory response in yellowfin snapper spleen, liver, and brain tissue. To examine its pathogenicity and antibiotic susceptibility, we analyzed the genome sequence of this strain with third-generation high-throughput technology. The VH-AQ-SCAU-GZ23 genome was found to comprise a circular chromosome and three plasmids. Virulence factor analysis indicated that VH-AQ-SCAU-GZ23 contains a TLH gene encoding a thermolysin that increases virulence. Additionally, several antibiotic resistance genes were identified, including those encoding β-lactams, tetracyclines, aminoglycosides, quinolones, macrolides, peptides, and other antibiotics. To assess the drug sensitivity of those antibiotic resistance genes, we cloned ten resistance genes and transfected them into Escherichia coli DH5α for drug susceptibility testing. These resistance genes enhanced the resistance of DH5α to streptomycin, ampicillin, and penicillin G, among other antibiotics. Our study provides crucial support and a theoretical basis for advancing understanding of Vibrio harveyi. The insights gained are expected to provide guidance for future endeavors aimed at preventing and managing marine bacterial infections.

Integrative paleophysiology of the metriorhynchoid Pelagosaurus typus (Pseudosuchia, Thalattosuchia).

Paleophysiology is an emergent discipline. Organismic (integrative) approaches seem more appropriate than studies focusing on the variation of specific features because traits are tightly related in actual organisms. Here, we used such an organismic approach (including lifestyle, thermometabolism, and hunting behavior) to understand the paleobiology of the lower Jurassic (Toarcian) thalattosuchian metriorhynchoid Pelagosaurus typus. First, we show that the lifestyle (aquatic, amphibious, terrestrial) has an effect on the femoral compactness profiles in amniotes. The profile of Pelagosaurus indicates that it was amphibious, with a foraging activity in shallow marine environments (as suggested by the presence of salt glands) and thermoregulatory basking behavior in land (as suggested by the presence of osteoderms with highly developed ornamentation). As for the thermometabolism, we show that the mass-independent resting metabolic rate of Pelagosaurus is relatively high compared to the sample of extant ectothermic amniotes, but analysis of vascular canal diameter and inferences of red blood cell size refute the hypothesis suggesting incipient endothermy. Finally, the foraging behavior was inferred using two proxies. Pelagosaurus had a mass-independent maximum metabolic rate and an aerobic scope higher than those measured in the almost motionless Iguana iguana, similar to those measured in the sit-and-wait predator Crocodylus porosus but lower than those quantified in the active hunter Varanus gouldii. These results suggest that Pelagosaurus may have had a hunting behavior involving a slow sustained swimming or a patient waiting in shallow waters, and may have caught preys like gharials, using fast sideways sweeping motions of the head.

Affective Oceanic Seaswimming and Encounters for Care-Full Environmental Communication

ABSTRACT Our oceanic swimming practice began as part of the project of doing scholarship differently in contemporary South African post-apartheid contexts. Swimming-writing-reading not only enables different ways of doing inquiry but also prompts new ways of communicating environmental injustices as we face them in/with/through the ocean. We argue the value of this practice, and the writings we generate and share, for a rethinking and reframing of environmental communication through practices of care. “Slow swimming” in the ocean brings one into intimate, affecting encounters with the ocean and its multiplicities. Porous to fluid temporalities, oceanic swimming-writing-reading becomes a hauntological place-space-time-mattering practice of swimming as we become aware of sedimented crimes of slavery and colonization, and confront the ghosts of apartheid and colonial violence. As we meet disasters of present and future, polluted and violated seas, our affective relational watery encounters with more-than-human species sharpen our response-ability to and responsibility for anthropocentric damages to the ocean and planet. We suggest such practices of affective wit(h)nessing, relationality, and care as a productive resource for communicating current environmental challenges that are consequences of certain human hands, as well as our mutual entanglements and response-abilities on planet Earth.

Intermittent swimming and muscle power output in brook trout, Salvelinus fontinalis.

Slow and sustainable intermittent swimming has recently been described in several Centrarchid fishes, such as bluegill and largemouth bass. This swimming behavior involves short periods of body-caudal fin undulation alternating with variable periods of coasting. This aerobic muscle powered swimming appears to reduce energetic costs for slow, sustainable swimming, with fish employing a "fixed-gear" or constant tailbeat frequency and modulating swimming speed by altering the length of the coasting period. We asked if this swimming behavior was found in other fish species by examining volitional swimming by brook trout in a static swimming tank. Further, we employed muscle mechanics experiments to explore how intermittent swimming affects muscle power output in comparison to steady swimming behavior. Brook trout regularly employ an intermittent swimming form when allowed to swim volitionally, and consistently showed a tailbeat frequency of ~2 Hz. Coasting duration had a significant, inverse relationship to swimming speed. Across a range of slow, sustainable swimming speeds, tailbeat frequency increased modestly with speed. The duration of periods of coasting decreased significantly with increasing speed. Workloop experiments suggest that intermittent swimming reduces fatigue, allowing fish to maintain high power output for longer compared to continuous activity. This study expands the list of species that employ intermittent swimming, suggesting this behavior is a general feature of fishes.

Time budget and behavioral synchrony of humpback whale mother‐calf pairs on a breeding ground in the southwestern Indian Ocean

AbstractUnderstanding the activity budget of mother‐young pairs can inform how energy is allocated and its relation to the development of young. Using suction cup tag data collected off Sainte Marie, Madagascar, during the calving season, we compared the time budgets of mothers and their calves in capital‐breeding humpback whales, investigated the changes with age, and assessed mother‐calf behavioral synchrony based on their swimming speed. We found that mothers and calves allocated much of their time to low‐level activities (i.e., static/quasi‐static or swimming at low speed). Young calves engaged more in slow swimming than older calves and mothers. Mothers with younger calves tended to stay static or quasi‐static less than mothers with older ones. Calves displayed some degree of independence in activities but were also observed synchronizing their activities with their mothers. Depending on the nature of the activity, the initiation of it was driven by either the calf or the mother. Our study provides additional knowledge for understanding the behavioral dynamics and interactions within humpback whale mother‐calf pairs. It provides data that can support the implementation of conservation measures.

Isolation and the pathogenicity characterization of Decapod iridescent virus 1 (DIV1) from diseased Macrobrachium nipponense and its activation on host immune response

The high morbidity and mortality of Macrobrachium nipponense occurred in several farms in China, with cardinal symptoms of slow swimming, loss of appetite, empty of intestine, reddening of the hepatopancreas and gills. The pathogen has been confirmed as Decapod Iridescent Virus 1 (DIV1), namely DIV1-mn, by molecular epidemiology, histopathological examination, TEM observation, challenge experiment, and viral load detection. Histopathological analysis showed severe damage in hepatopancreas and gills of diseased prawns, exhibited few eosinophilic inclusions and pyknosis, and TEM of diseased prawns revealed that icosahedral virus particles existed in hepatopancreas and gill, which confirmed the disease of the farmed prawns caused by the DIV1 infection. Besides, challenge tests showed LD50 of DIV1 to M. nipponense was determined to be 2.14 × 104 copies/mL, and real-time PCR revealed that M. nipponense had a very high DIV1 load in the hemocytes, gills and hepatopancreas after infection. Furthermore, qRT-PCR was undertaken to investigated the expression of six immune-related genes in DIV1-infected M. nipponense after different time points, and the results revealed UCHL3, Relish, Gly-Cru2, CTL, MyD88 and Hemocyanin were significantly up-regulated in hemocytes, gills and hepatopancreas, which revealed various expression patterns in response to DIV1 infection. This study revealed that DIV1 infection is responsible for the mass mortality of M. nipponense, one of the important crustacean species, indicating its high susceptibility to DIV1. Moreover, this study will contribute to exploring the interaction between the host and DIV1 infection, specifically in terms of understanding how M. nipponense recognizes and eliminates the invading of DIV1.

Design and Reality-Based Modeling Optimization of a Flexible Passive Joint Paddle for Swimming Robots.

Rowing motion with paired propellers is an essential actuation mechanism for swimming robots. Previous work in this field has typically employed flexible propellers to generate a net thrust or torque by using changes in the compliance values of flexible structures under the influence of a fluid. The low stiffness values of the flexible structures restrict the upper limit of the oscillation frequency and amplitude, resulting in slow swimming speeds. Furthermore, complex coupling between the fluid and the propeller reduce the accuracy of flexible propeller simulations. A design of a flexible passive joint paddle was proposed in this study, and a dynamics model and simulation of the paddle were experimentally verified. In order to optimize the straight swimming speed, a data-driven model was proposed to improve the simulation accuracy. The effects of the joint number and controller parameters on the robot's straight swimming speed were comprehensively investigated. The multi-joint paddle exhibited significantly improved thrust over the single-joint paddle in a symmetric driving mode. The data-driven model reduced the total error of the simulated data of the propulsive force in the range of control parameters to 0.51%. Swimming speed increased by 3.3 times compared to baseline. These findings demonstrate the utility of the proposed dynamics and data-driven models in the multi-objective design of swimming robots.

A Biomimetic Piezoelectric Composite‐Driven Undulation Underwater Robotic Structure: Characteristic Analysis and Experimental Investigation

Numerous proposals and recommendations have been made in the development of underwater undulation robots, but very few studies have focused on the undulation characteristics of undulation robots. The undulating mode of the clearnose skate utilizing the activation of the pectoral fins in undulatory bursts is particularly suitable for slow and efficient swimming. Inspired by the working principle of the clearnose skate, herein, an undulation robotic structure is presented. Considering the hydrodynamic skeleton and propulsion mechanism of the clearnose skate, the solution is based on a piezoelectric composite for realizing undulatory propulsion. This approach leverages the converse piezoelectric effect and modal coupling to produce the desired undulating motion, thereby achieving the undulation design of the robot. The proposed robotic structure can realize the propulsion mode using piezoelectric composites to undulate in the same direction and can use the clockwise or counterclockwise undulation of piezoelectric composites to achieve the steering mode. In addition, finite element analysis is employed as an approach to investigate the undulation characteristics and transient vibration characteristics of the robot. The operational efficiency of the robotic structure is assessed through experiments. The results show that the propulsion mode achieves the speed of 3.33 body‐length s−1. The steering mode exhibits the steering velocities of 17.4 deg s−1.

Combined effect of anthracene and polyethylene microplastics on swimming speed and cytochrome P4501A monooxygenase expression of Java medaka (Oryzias javanicus).

Microplastics have been detected in a variety of aquatic ecosystems, and the combined effect of microplastics and chemical pollutants has become a matter of increasing concern. We conducted a 12-d co-exposure test of anthracene and spherical or fragmented polyethylene microplastics (size 200 µm) on Java medaka (Oryzias javanicus). The accumulation of anthracene in Java medaka muscle reached a plateau on day 5 in all anthracene exposure groups, and no significant differences were detected among the groups (ANT, 20.4 ± 5.5; ANT + SPPE-MP, 24.7 ± 2.7; ANT + FRPE-MP, 24.6 ± 4.7 µg/g). However, co-exposure to anthracene and spherical or fragmented polyethylene microplastics increased the duration of slow swimming in a swimming behavior test (control, 4.1 ± 1.4; ANT, 5.2 ± 2.8; ANT + SPPE-MP, 12.4 ± 3.7; ANT + FRPE-MP, 17.4 ± 5.1 min/30 min), and co-exposure to anthracene and fragmented polyethylene microplastics induced higher cytochrome P4501A monooxygenase (CYP1A) expression in Java medaka livers than the other anthracene exposure groups (ANT, 189 ± 74; ANT + SPPE-MP, 203 ± 75; ANT + FRPE-MP 272 ± 36% of control). Polyethylene microplastics appear to be weak vectors of anthracene at the size tested (200 µm), and the effect of shape (spherical or fragmented) on the vector effect was small. However, the presence of polyethylene microplastics could affect the swimming behavior and CYP1A expression in Java medaka.

Boldness behavior and ecological adaptability of stone moroko (Pseudorasbora parva) in open-field testing

Abstract Boldness is closely related to fish species’ adaptative strategies and invasiveness and has become the focus of fish personality research. However, due to the lack of studies on behavioral stages, the ecological functions of certain behaviors remain unclear. To better understand the link between boldness and invasiveness in stone moroko (Pseudorasbora parva), an invasive Asian fish species, we exposed the fish to an open-field environment for 60 min and assessed their behavioral patterns, profiles, and stages. The results show that the boldness behavior of stone moroko was characterized by high activity, low average velocity, and diverse swimming postures. Five behavioral stages with significant differences were revealed: outbreak, inhibition, slow swimming, exploration, and adaptation. These observations suggest that stone moroko can quickly habituate to new environments. In addition, stone moroko spent more energy on exploring the living area and less on environmental risk assessment, as revealed by an analysis of their energy trade-off strategy. The behavioral strategies of stone moroko may explain their extremely high environmental adaptability and ability to invade multiple environments.

Chafing behaviour from two carcharhinid shark species Carcharhinus falciformis and C. galapagensis on whale sharks Rhincodon typus

This report provides observations regarding chafing interactions from two carcharhinid species, the silky shark, Carcharhinus falciformis and the Galapagos shark, C. galapagensis, on whale sharks, Rhincodon typus, in the Revillagigedo National Park, Mexico. Four events were observed between 2013 and 2019 by means of SCUBA diving and drone aerial surveys. These interactions appeared to be casual and triggered by the large dimensions and slow swimming speed of the whale sharks.

Susceptibility of Fluvalinate and Esfenvalerate on Adult Tarek Alburnus tarichi (Güldenstädt 1814)

Abstract Fluvalinate and esfenvalerate are pyrethroid insecticides and are used to control insect pests. These pesticides can enter the aquatic environment in different ways after use, causing toxicity. Tarek is a fish of the Cyprinidae family native to the Lake Van basin in Turkey. This study was conducted to determine the acute toxicity of fluvalinate and esfenvalerate to adult tarek. In the bioassays, tarek with an average length of 20.6±1.2 cm and an average weight of 93.9±14.0 g were used for fluvalinate, while an average length of 19.7±1.2 cm and an average weight of 85.5±16.6 g were used for esfenvalerate. Fish were exposed to fluvalinate using the semi-static test method, and esfenvalerate using the static test method. The toxicity tests were performed under the natural photoperiod. The concentrations used for fluvalinate were 0.15, 0.30, 0.45, 0.60 µg L−1, while for esfenvalerate they were 0.33, 0.67, 1.00, 1.34 µg L−1. The tests were performed at 13±1 °C for 96 hours with dechlorinated tap water. At the end of the toxicity tests, the mean lethal concentration (LC50) of fluvalinate after 96 hours was determined to be 0.338 (0.230-0.477) µg L−1 and the above concentration of esfenvalerate was determined to be 0.475 (0.293-0.640) µg L−1 for adult tarek. Tarek exposed to fluvalinate and esfenvalerate showed toxic effects throughout the test, such as splashing, vigorous and then slower swimming, loss of balance, increased respiratory rate and contraction. Consequently, fluvalinate and esfenvalerate were found to be highly toxic to tarek and therefore the concentration of fluvalinate should not exceed 0.003 µg L−1, and that of esfenvalerate should not exceed 0.005 µg L−1 in freshwater environments where tarek lives.

Rapid Change in the Direction of Hand Movement to Increase Hand Propulsion During Front Crawl Swimming.

This study aims to investigate the difference in hand acceleration induced by rapid changes in hand movement directions and propulsion between fast and slow groups of swimmers during front crawl swimming. Twenty-two participants, consisting of 11 fast and 11 slow swimmers, performed front crawl swimming at their maximal effort. Hand acceleration and velocity and the angle of attack were measured using a motion capture system. The dynamic pressure approach was used to estimate hand propulsion. In the insweep phase, the fast group attained significantly higher hand acceleration than the slow group in the lateral and vertical directions (15.31 [3.44]m·s-2 vs 12.23 [2.60]m·s-2 and 14.37 [1.70]m·s-2 vs 12.15 [1.21]m·s-2), and the fast group exerted significantly larger hand propulsion than the slow group (53 [5]N vs 44 [7]N). Although the fast group attained large hand acceleration and propulsion during the insweep phase, the hand velocity and the angle of attack were not significantly different in the 2 groups. The rapid change in hand movement direction could be considered in the technique of underwater arm stroke, particularly in the vertical direction, to increase hand propulsion during front crawl swimming.

Salad Days: Pairwise Gene Edits Food to Topple Nutrition Barriers

Salad Days: Pairwise Gene Edits Food to Topple Nutrition Barriers

Determination of the Acute and Chronic Toxicity of Sulfate from the Sulfur Autotrophic Denitrification Process to Juvenile Zebrafish (Danio rerio).

Sulfur-based materials are widely used as electron donors for denitrification to enhance nitrogen removal from water. This leads to an increased sulfate concentration in the effluent or sulfate accumulation in recirculating aquaculture systems. This study explored acute and chronic toxicity of sulfate to juvenile zebrafish (Danio rerio) and investigated the histopathological changes in the gills of juvenile zebrafish exposed to sulfate. Results show that zebrafish had a high tolerance to sulfate, with no acute toxicity at sulfate concentrations from 250 to 3200 mg/L. For the chronic toxicity study, it was found that zebrafish mortality decreased with the increase in sulfate concentrations ranging from 250 to 1500 mg/L. In contrast, when the sulfate concentration was 1500-3000 mg/L, zebrafish mortality increased with the increasing sulfate concentration. In addition, in the ion balance test, KCl was added to balance the effects of Na+ from the Na2SO4 used to obtain the desired sulfate concentrations, showing that fish mortality correspondingly increased with increasing KCl addition. Furthermore, when living in an environment with elevated sulfate concentrations for a long period, changes were observed in the morphology, behavior, and gill tissue of the zebrafish, including slow and lateral swimming; bottom settling; and large opening and closing, lamellar fusion, and necrosis of gills. This research reveals the toxicity of sulfate to aquatic organisms, providing a scientific basis for the promotion and application of sulfur or sulfur-based materials in autotrophic reduction processes for wastewater treatment.

Skull and partial skeleton of a new pachycetine genus (Cetacea, Basilosauridae) from the Aridal Formation, Bartonian middle Eocene, of southwestern Morocco.

Pachycetus paulsonii, Pachycetus wardii, and Antaecetus aithai are middle Eocene archaeocete whales found in Europe, North America, and Africa, respectively. The three are placed in the new basilosaurid subfamily Pachycetinae. Antaecetus is a new genus known from Egypt and Morocco, and the only pachycetine known from a substantial postcranial skeleton. The skull of A. aithai described here resembles that of Saghacetus osiris in size, but lacks the narrowly constricted rostrum of Saghacetus. Antaecetus is smaller than Pachycetus and its teeth are more gracile. Upper premolars differ in having two rather than three accessory cusps flanking the principal cusp. Pachycetines differ from dorudontines in having elongated posterior thoracic and lumbar vertebrae like those of Basilosaurus, but differ from basilosaurines and from dorudontines in having conspicuously pachyosteosclerotic vertebrae with dense and thickly laminated cortical bone surrounding a cancellous core. Pachycetinae are also distinctive in having transverse processes on lumbar vertebrae nearly as long anteroposteriorly as the corresponding centrum. We infer from their pachyosteosclerotic vertebrae that pachycetines were probably sirenian-like slow swimmers living in shallow coastal seas and feeding on passing fish and mobile invertebrates.

Effect of Maggot Flour (Hermetia illucens larvae) on Histopathology of Koi carp <I>(Cyprinus carpio)</I> Muscles and Gills Infected with <I>Edwarsiella tarda</I>

Highlight Research Feeding of maggot flour formulations to koi carp infected with tarda Active compounds contained in maggot Clinical symptoms of koi carp infected with tarda Damage to the muscle and gill tissue of koi carp infected with E. tarda Abstract The problem that fishes farmers often face is disease. Maggot contains a high protein which ranges from 41-42%. Besides that, maggot also has a good effect on increasing the body resistance of fish. While the maggot provision fulfills nutritional need, it’s also expected to boost immunity against bacterial disease. One of which is Edwardsiella tarda, known to infect koi carp (Cyprinus carpio). Feeding of maggot flour at different doses, namely A (25%), B (50%), C (75%), and D (100%) was carried out to determine its effect on the histopathology of the muscles and gills of C. carpio infected with E. tarda. Water quality during the study obtained an average value, namely the temperature ranging from 26-27.5℃, pH 6.5-8.1, and DO 5.2-8 mg/L. Fish infected with E. tarda showed several clinical symptoms, including rapid operculum movement, irregular and slow swimming, and bleeding on the skin. The results of the histopathological analysis showed that in muscle and gill tissue, treatment C (75%) showed the lowest damage value among other treatments with an average score of necrosis 0.93, hyaline degeneration 1.33, and Edema 1.27. Average score of gill tissue damage was 0.9 fusion, 1.3 congestion, 0.9 hyperplasia. Based on this, the provision of maggot flour can be used to prevent infection of E. tarda against C. carpio.

The redescription of the holotype of Nothosaurus mirabilis (Diapsida, Eosauropterygia)-a historical skeleton from the Muschelkalk (Middle Triassic, Anisian) near Bayreuth (southern Germany).

In 2009, the historical mount of the holotype of Nothosaurus mirabilis from the Upper Muschelkalk of Oschenberg (Laineck Mountain Range, near Bayreuth, southern Germany) was disassembled and the original postcranial skeleton was reworked and remounted in find position. Its morphology is described and figured for the first time in detail. Further on, a thorough overview of the sedimentary environment and the historical activities around the Upper Muschelkalk quarries in the vicinity of Bayreuth is given. The holotype of N. mirabilis is one out of only two fairly complete nothosaur skeletons known from the Bayreuth Upper Muschelkalk and greatly emends our knowledge of the morphology of the species and the genus. It will further allow an assignment of isolated elements to this taxon. The specimen consists of an articulated and complete neck and anterior trunk vertebral column as well as several articulated parts of the anterior tail region. The sacral region is partially preserved but disarticulated. Besides vertebrae, ribs and gastral fragments, both humeri, the right femur, few zeugopodial and autopodial elements, and the right pelvic girdle are preserved. The very high neural spines of the holotype are stabilized by a supersized zygosphene-zygantrum articulation reaching far dorsally. Together with the large intercentral spaces this character suggests lateral undulation of the trunk region during fast swimming whereas propelling with the broad and wing-shaped humerus and the flat ulna was used during slower swimming. The total body length for this not fully grown individual is reconstructed as between 290 to 320 cm. Preservation, degree of completeness, and articulation of the individual is unique. The skull and shoulder girdle are both lost, whereas articulated strings of the vertebral column have turned and appendicular bones have shifted posteriorly or anteriorly, respectively, indicating water movements and possibly also scavenging.

The persistent-predation strategy ofthered lionfish (Pterois volitans).

The pursuit of prey is vital to the biology of a predator and many aspects of predatory behaviour are well-studied. However, it is unclear how a pursuit can be effective when the prey is faster than a non-cryptic predator. Using kinematic measurements, we considered the strategy of red lionfish (Pterois volitans) as they pursued a faster prey fish (Chromis viridis) under laboratory conditions. Despite swimming about half as fast as C. viridis, lionfish succeeded in capturing prey in 61% of our experiments. This successful pursuit behaviour was defined by three critical characteristics. First, lionfish targeted C. viridis with pure pursuit by adjusting their heading towards the prey's position and not the anticipated point of interception. Second, lionfish pursued prey with uninterrupted motion. By contrast, C. viridis moved intermittently with variation in speed that included slow swimming. Such periods allowed lionfish to close the distance to a prey and initiate a suction-feeding strike at a relatively close distance (less than 9 cm). Finally, lionfish exhibited a high rate of strike success, capturing prey in 74% of allstrikes. These characteristics comprise a behaviour that we call the 'persistent-predation strategy', which may be exhibited by a diversity of predators with relatively slow locomotion.

Wild fish beat the heat

Wild animals can adapt to a wide range of temperatures. The ability to perform well in a constantly changing environment is called physiological plasticity. Physiological plasticity allows ectothermic animals, such as fishes, to maintain their metabolism even when the water that the fish is in heats up or cools down wildly. Fishes living in laboratories are less likely to have experienced temperature changes, so will their metabolism still perform well if there is a big temperature shift in their tank? Or have they lost their physiological plasticity because they have only experienced steady temperatures for more than 150 generations? Can living in steady environments affect a fish's behavior, metabolism or gene expression compared with living in a more turbulent environment? To study these questions, Rachael Morgan and colleagues from the Norwegian University of Science and Technology and the University of Greenwich, UK, compared the physiological plasticity of two populations of zebrafish: a wild population collected from India and a population raised in the lab. They aimed to understand whether living in a stable environment can change a fish's ability to perform when there is a big change in temperature.The researchers collected 300 zebrafish from the two populations and exposed each group to a variety of temperatures (from 10 to 38°C) for 1 month. They then measured the fish's swimming ability, escape response, growth rate, metabolic rate and gene expression and compared the measurements of the two groups to learn whether the lab-raised group had more difficulty in adapting to large temperature shifts than the wild group because they have less physiological plasticity.Sure enough, the lab-raised fish were less able to adjust to temperature change than the fish that had come from India. The lab-raised zebrafish were slower swimmers than wild zebrafish at all temperatures, and when escaping, lab-raised zebrafish responded more slowly than wild zebrafish, especially when in colder temperatures. In addition, the lab-raised zebrafish grew faster than the wild zebrafish, likely because domesticated animals are selected for faster growth rates. When comparing metabolism between the groups, the researchers measured the range of temperatures at which the fish could reach their maximum metabolic rates. They found that lab-raised fish could only reach their maximum metabolic rate in water temperatures between 26 and 36°C, but wild fish could reach their maximum metabolic rate over a much broader temperature range (21–38°C). Gene expression was also different among the two groups. The lab fish had greater levels of proteins that deal with stress compared with the wild fish. Interestingly, very cold temperatures were especially difficult for both groups, which may suggest that physiological plasticity is limited at these extreme temperatures.This study tells us that lab domestication affects the ability of animals to adjust to changes in their environment across several biological levels, from behaviour to gene expression. With this knowledge, scientists should take into account that domestication can change animals’ responses to an experiment when choosing study animals. Morgan and colleagues also suggest that there may be a trade-off between high levels of physiological plasticity and growth rates and warn that domestication can quickly lead to a loss of physiological plasticity.