Differences In Swimming Ability Research Articles

Divergent responses in the gut microbiome and liver metabolome to ammonia stress in three freshwater turtles

Ammonia is a common pollutant in aquaculture system, and toxic to all aquatic animals. However, different aquatic animals exhibit diverse physiological responses to high-level ammonia exposure, potentially indicating their divergent resistance to ammonia stress. In this study, juveniles of three freshwater turtles (Mauremys reevesii, Pseudemys nelsoni and Trachemys scripta elegans) were exposed to different concentrations of ammonia (0, 0.3 and 3.0 mg/L) for 30 days, and their swimming, growth performance, gut microbiota, and hepatic metabolites were measured to evaluate the interspecific difference in physiological responses to ammonia stress. Despite no differences in swimming ability, growth rate, and gut microbial diversity, observable changes in microbial community composition and hepatic metabolite profiles were shown in ammonia-exposed turtles. A relatively higher abundance of potentially pathogenic bacteria was found in M. reevesii than in the other two species. Moreover, microbial compositions and metabolic responses differed significantly among the three species. M. reevesii was, out of the three tested species, the one in which exposure to ammonia had the greatest effect on changes in bacterial genera and hepatic metabolites. Conversely, only a few metabolites were significantly changed in T. scripta elegans. Integrating these findings, we speculated that native M. reevesii should be more vulnerable to ammonia stress compared to the invasive turtle species. Our results plausibly reflected divergent potential resistance to ammonia among these turtles, in view of differential physiological responses to ammonia exposure at environmentally relevant concentrations.

Socioeconomic differences in swimming ability among children in Malmö, southern Sweden: Initial results from a community-level intervention.

Aims: To investigate to what extent socioeconomic differences in swimming abilities persist among children in the city of Malmö, Sweden, after a community-level swimming intervention programme in public primary schools. Methods: A compulsory swimming education programme was launched in 2014 in second grade (at age 8) in all public primary schools in Malmö, Sweden. Data for the present study on sociodemographic conditions and self-reported swimming ability in fourth grade (age 10) were used for the last birth cohort unexposed (n = 1695) and the first birth cohort exposed (n = 1773) to the intervention. Results: The swimming ability was 78 and 77%, respectively, in the pre- and post-intervention cohorts. Significantly lower self-reported swimming ability was found both pre- and post-intervention among children with support activities in school, with parents born outside Europe, North America and Australia, with manual working, unemployed or studying parents and in children enrolled in schools with socioeconomic index below median. Conclusions: The findings do not suggest that sociodemographic differences in swimming ability have decreased in the first birth cohort exposed to the community-level intervention in Malmö. Striking differences in self-reported swimming ability were noted when the children reached the fourth grade both pre- and post-intervention with marked lower abilities in socially disadvantaged groups. Monitoring of swimming abilities should continue for the present, and similar interventions aimed at reducing inequalities among children. Efforts to increase water comfort at preschool age ought to be considered.

Morphological but no genetic differentiation among fragmented populations of Hemiculter leucisculus (Actinopterygii, Cyprinidae) from a lake complex in the middle Yangtze, China

Understanding the adaptive responses of fish to different local habitats is important for assessing fragmentation effects and directing conservation management. In this study, morphological and genetic differentiations were tested among Hemiculter leucisculus populations from three lakes, i.e., the Liangzi, Niushan, and Biandantang Lakes, fragmented from the Liangzi Lake complex in the middle Yangtze. These lakes have different habitat environments, largely influenced by their size and connection patterns with the mainstem, and also have different timings of fragmentation in the complex. Morphological differentiations among populations in the lakes were expected to reflect population responses to local habitat conditions. Genetic differentiation was expected to occur due to isolation of the populations. Our results revealed statistically significant morphological differences and no genetic differentiation among populations from the lakes. Morphometric differences might be related to swimming ability of the fish in different habitats. Population genetics results showed that all individuals constituted a single population. However, a recent reduction in gene flow between the lakes, a loss of alleles, and low genetic diversity were found, suggesting probable genetic impacts of fragmentation. These results suggest that phenotypic plasticity might contribute to morphological differences in the differing local conditions, and this interpretation needs confirmation from further experiments testing the roles of these morphological differences in swimming ability and the differing environments in generating these differences. Our results have led to a better understanding of the responses of fish populations to habitat fragmentation and can thus direct the connectivity restoration of fragmented habitats in the Yangtze River.

Differences in swimming ability and its response to starvation among male and female Gambusia affinis.

ABSTRACTTo explore the differences in the swimming ability and environmental adaptive abilities between male and female Gambusia affinis, we assessed the differences in burst swimming speeds (Uburst), critical swimming speeds (Ucrit) and their related fin areas, and consumption of energy substances after starvation at 0 (control group), 15, 30, 45, and 60 days, respectively. The results showed that the pectoral and caudal fin areas did not differ significantly between male and female G. affinis. However, the dry mass, condition factors, and absolute contents of glycogen, lipids, and proteins were significantly elevated in females in the control group (P<0.05), whereas Uburst and Ucrit were significantly low (P<0.05). After starvation of 60 days, the rate of consumption of lipids was significantly low in the females (P<0.05). Although Uburst and Ucrit decreased linearly with increased duration of starvation, the coefficient of linear equation between Ucrit and starvation time was significantly lower in females than males (P<0.05). These findings indicated that low body mass and condition factors reduce the relative bear load and moving resistance that causes high swimming performance in male G. affinis. High contents of energy substances and low rate of consumption of lipids result in stable Ucrit in females during hunger.

International travelers and unintentional fatal drowning in Australia--a 10 year review 2002-12.

. Drowning deaths of travelers are commonly reported in the media, creating a perception that they are at a higher risk of drowning than residents. This may be true, due in part to unfamiliarity with the risks posed by the hazard, however there is limited information about drowning deaths of travelers in Australia. This study aims to identify the incidence of drowning among international travelers in Australia and examine the risk factors to inform prevention strategies. . Data on unintentional fatal drowning in Australian waterways of victims with a residential postcode from outside Australia were extracted from the Royal Life Saving Society-Australia National Fatal Drowning Database. . Between 1 July 2002 and 30 June 2012 drowning deaths among people known to be international travelers accounted for 4.3% (N = 123) of the 2870 drowning deaths reported in Australian waterways. Key locations for drowning deaths included beaches (39.0%), ocean/harbour (22.0%) and swimming pools (12.2%). Leading activities prior to drowning included swimming (52.0%), diving (17.9%) and watercraft incidents (13.0%). . International travelers pose a unique challenge from a drowning prevention perspective. The ability to exchange information on water safety is complicated due to potential language barriers, possible differences in swimming ability, different attitudes to safety in the traveler's home country and culture, a lack of opportunities to discuss safety, a relaxed attitude to safety which may result in an increase in risk taking behaviour and alcohol consumption. . Prevention is vital both to reduce loss of life in the aquatic environment and promote Australia as a safe and enjoyable holiday destination for international travelers.

Swimming and Gendered Vulnerabilities: Evidence from the Northern and Central Philippines

Men and women's vulnerability to disasters is different and often related, in part, to cultural norms that influence gendered behaviors and abilities. In this study we focus on gender differences in swimming abilities, which in the case of tsunamis have resulted in far greater female mortality rates. We present results on swimming ability by gender for 940 residents of coastal rural communities in the northern and central Philippines. We also examine cross-generational transmission of swimming abilities to shed light on future vulnerability. Results reveal men are far more likely than women to swim and, importantly, parents who can swim are more likely to have children who can swim. In this way, differences in swimming ability among today's adults may perpetuate vulnerabilities within future generations.

Behaviour of two small pelagic and demersal fish species in diverse hydraulic environments

ABSTRACTIncreased hydraulic diversity could be a means to promote fish diversity in rivers, but little is known of the behaviour of fish in hydraulic environments. This study concerns the behaviour of two species of small native Australian freshwater fish in variable hydraulic environments and ecological habit, with regard for (a) whether the apparent differences in swimming ability are reflected in the behaviour of the species and (b) the influence of changing hydraulic conditions on their patterns of use. An artificial channel was constructed with three levels of discharge, and fish were allowed to swim freely for 3 h without human interference. Their movements and habitat choices reflected their swimming ability and ecological habit, in that the stronger swimming, pelagic common galaxias (Galaxias maculatus) spent most time cruising in the open channel, preferring the turbulent inflow, and the demersal flat‐headed gudgeon (Philypnodon grandiceps) remained in the shelter of boulders. In effect, the galaxias changed their behaviour with changes in hydraulic conditions, while the gudgeons continued to use their preferred habitat. This study, therefore, provides support for the use of hydraulic diversity as a tool to foster fish diversity. Copyright © 2010 John Wiley &amp; Sons, Ltd.

The effects of perceived predation risk on pre‐ and post‐metamorphic phenotypes in the common frog

AbstractWhere organisms undergo radical changes in habitat during ontogeny, dramatic phenotypic reshaping may be required. However, physiological and functional interrelationships may constrain the extent to which an individual's phenotype can be equally well adapted to their habitat throughout the life cycle. The phenotypic response of tadpoles to the presence of a predator has been reported for several species of anuran but the potential post‐metamorphic consequences have rarely been considered. We reared common frog Rana temporaria tadpoles in the presence or absence of a larval odonate predator, Aeshna juncea, and examined the consequences of the resulting phenotypic adjustment in the aquatic larval stage of the life cycle for the terrestrial juvenile phenotype. In early development tadpoles developed deeper tail fins and muscles in response to the predator and, in experimental trials, swam further than those reared in the absence of a predator. While the difference in swimming ability remained significant throughout the larval period, by the onset of metamorphosis we could no longer detect any differences in the morphological parameters measured. The corresponding post‐metamorphic phenotypes also did not initially differ in terms of morphology. At 12 weeks post‐metamorphosis, however, froglets that developed from predator‐exposed tadpoles swam more slowly and less far than those that developed from tadpoles reared in the absence of predators, the opposite trend to that observed in the larval stage of the life cycle, and had narrower femurs. These results suggest that there may be long‐term costs for subsequent life‐history stages of tailoring the larval phenotype to prevailing environmental conditions.

Ca2+handling and oxidative capacity are greatly impaired in swimming muscles of hatchery-reared versus wild Atlantic salmon (Salmo salar)

The swimming capacity of fish is strongly associated with muscle performance, although the prerequisites for effective movements have not been fully described at the molecular level. To compare the condition of swimming musculature of hatchery-reared Atlantic salmon (Salmo salar) with that of wild fish, we analyzed the relative level of two excitation–contraction coupling components (i.e., dihydropyridine receptor (DHPR) and ryanodine receptor (RyR)) and the oxidative capacity of muscles with histochemical and Western blot methods. The density of DHPR and RyR was considerably higher in swimming muscles of wild fingerlings (age 0+) (109.8% and 123.3% in red muscle; 128.6% and 186.0% in white muscle, respectively) and yearlings (age 1+) (153.5% and 459.1% in red muscle; 131.2% and 858.4% in white muscle) as compared with those in reared fish. Similar difference was also observed in the oxidative capacity of muscles. Moreover, the oxidative activity correlated positively with the level of DHPR and RyR. Our data indicate that calcium handling, as well as oxidative capacity of swimming muscles of reared salmon, is clearly separable from the corresponding capacities of wild fish. We suggest that the observed alteration is a major contributing factor to the well-documented differences in swimming ability between wild and hatchery-reared salmon.

Location influences size-selective predation on newly settled reef fish

Demersal fish usually settle to established fish assemblages that include suites of gape-limited predators, whose compositions vary among locations. We investigated the extent to which predation was size-selective on a species of newly settled coral reef fish, the damselfish Pomacentrus amboinensis (Bleeker 1868), among 3 lagoonal sites on 1 reef. The 3 sites at Lizard Island, Great Barrier Reef, Australia, differed in species composition and relative abundance of predators. Fish at the end of their larval phase were caught in light traps and tattooed for individual recognition. They were then paired so that there was a 1 mm difference between partners, and placed on small patch reefs at the base of the 3 shallow lagoonal sites. Large individuals survived significantly better than small individuals in 1 out of 3 sites. One site displayed the reverse trend, even though non-significant, and the third site showed no evidence of selection. Selection was strongest at the site where predators of small reef fishes were in highest densities and water currents were strongest. Strong water currents appeared to emphasise size-related differences in swimming ability and increase the vulnerability of small fish at this site. Our results suggested that the occurrence of size-selection for this species at settlement will depend on the composition of the predator assemblage and prevailing environmental conditions; these both interact with the performance attributes of prey, and all 3 variables may be location-specific.

Critical swimming speeds of late-stage coral reef fish larvae: variation within species, among species and between locations

The swimming abilities of larval fishes are important for their survival, potentially affecting their ability to avoid predators, obtain food and control dispersal patterns. Near settlement swimming abilities may also influence spatial and temporal patterns of recruitment. We examined Critical speed (U-crit) swimming ability in late stage larvae of 89 species of coral reef fishes from the Great Barrier Reef and the Caribbean. Coefficients of variation in U-crit calculated at the individual level were high (28.4%), and this was not explained by differences in size or condition factor of these same larvae. Among species U-crit ranged from 5.5 cm s−1 to 100.8 cm s−1 (mean=37.3 cm s−1), with 95% of species able to swim faster than the average current speed around Lizard Island, suggesting that most species should be capable of influencing their spatial and temporal patterns of settlement. Inter-specific differences in swimming ability (at both the family and species levels) were significantly correlated with size and larval morphology. Correlations were found between swimming performance and propulsive area, fineness ratio and aspect ratio, and these morphological parameters may prove useful for predicting swimming ability in other taxa. Overall, the swimming speeds of larvae from the same families at the two locations were relatively similar, although the Lutjanidae and Acanthuridae from the Caribbean were significantly slower than those from the great barrier reef. Differences in swimming speed and body form among late stage larvae suggests that they will respond differently to factors influencing survival and transport during their pelagic phase, as well as habitat use following settlement.

Wave exposure, swimming performance, and the structure of tropical and temperate reef fish assemblages

We examined the relationship between swimming performance, wave exposure, and the distribution patterns of labrids on temperate rocky reefs, in comparison with previous functional analyses of a tropical assemblage. Visual censuses of the distribution and abundance of labrids across two major gradients of wave exposure (depth and aspect to prevailing winds) were made at two offshore islands near Port Stephens, New South Wales, Australia. Distinct shifts in species composition and abundance were evident between high and low wave exposure habitats on temperate rocky reefs, particularly between deep and shallow habitats on exposed reef fronts. The swimming performances of temperate labrids were assessed through examination of pectoral fin shape (aspect ratio) and in situ swimming speeds. A diversity of pectoral fin morphologies was exhibited within this temperate assemblage, ranging from rounded to tapered fins (aspect ratios of 0.52 and 1.43, respectively). Fin shape was strongly correlated (Pearson’s correlation 0.884, P<0.001) with swimming speed (ranging from 1.05 and 3.06 body lengths s−1), in a relationship comparable to that observed in tropical labrids. Inter-specific differences in swimming ability provided some explanation for differences in the distribution and abundance of temperate labrids in relation to wave exposure. However, our findings suggest that although coral reef labrids appear to predominantly use high aspect-ratio fins to successfully occupy wave-exposed habitats, temperate labrids appear to be using an enhanced swimming ability through increased body size.

Differences in Swimming Ability and Behavior in Response to High Water Velocities among Native and Nonnative Fishes

We conducted swimming performance tests on native and nonnative fishes commonly found in Arizona streams to evaluate the extent of differences in swimming ability among species. Fishes with similar mean lengths were subjected to stepwise increases in water velocity in a laboratory swim tunnel until fish could no longer maintain position. Nonnative fathead minnows Pimephales promelas and red shiners Cyprinellalutrensis exhibited swimming abilities similar to native longfin dace Agosia chrysogaster, speckled dace Rhinichthys osculus and spikedace Meda fulgida. Nonnative mosquitofish Gambusia affinis exhibited swimming ability similar to native Gila topminnows Poeciliopsis occidentalis. Desert suckers Catostomus clarki, bluehead suckers Catostomus discobolus and speckled dace exhibited behavioral responses to high water velocities that may confer energetic advantages in swift water. Differences in swimming ability do not appear to adequately explain the disproportionate removal of nonnative fishes via flooding. Behavioral responses to high flows are more likely the mechanism that allows native fish to persist in streams during flood events.

Sexual difference in habitat use of Texas map turtles (Emydidae: Graptemys versa) and its relationship to size dimorphism and diet

Sexual differences in habitat use of map turtles (Graptemys spp.) have been attributed to differences in swimming ability as influenced by body size, because females are much larger than males, or to sexual differences in diet. Captures of young female Graptemys versa, which had body sizes similar to those of adult males but diet and trophic morphology more similar to those of larger females, allowed testing of these alternative hypotheses. A variety of single habitat variables measured at the sites of capture performed poorly in separating the three groups of turtles, but multivariate analysis and variables relating to position within the stream produced greater separation, indicating that complex combinations of factors probably influence habitat use. Young females were more similar in their habitat use to large females than to males, and their diet was also more similar to that of larger females, due primarily to the quantities of mollusks consumed. The data supported the hypothesis that habitat separation was the result of dietary rather than body size differences. While dietary differences are probably facilitated by sexual size dimorphism, they may not be the ultimate selective force that produced the size dimorphism.

Embryonic Velar Structure and Function of Two Sibling Species of Crepidula With Different Modes of Development

The structure and function of the embryonic velum of two closely related species of Crepidula with different modes of development are examined. The velum of C. dilatata, a direct developer whose embryos feed on nurse eggs, does not differ substantially from the velum of C. fecunda, a species with planktotrophic larvae. Although velar ciliation develops earlier in embryos of C. dilatata, embryos of both species were able to feed on small particles, using the opposed-band ciliary mechanism. However, the embryos of C. dilatata lose this ability as they grow. The embryos of C. dilatata were not able to swim, whereas those of C. fecunda swam consistently in vials of seawater. This difference in swimming ability is probably due to differences in velum-body size allometry between the two species.

Adult Learning Deficits after Neonatal Exposure tod-Methamphetamine: Selective Effects on Spatial Navigation and Memory

The effects of neonatal d-methamphetamine (MA) treatment on cued and spatial learning and memory were investigated. MA was administered to neonatal rats on postnatal days 11-20. All groups received four subcutaneous injections per day. Group MA40-4 received 40 mg. kg(-1). d(-1) of MA in four divided doses (10 mg/kg per injection). Group MA40-2 received 40 mg. kg(-1). d(-1) of MA in two divided (20 mg/kg/injection) and saline for the other two injections per day. Controls received saline for four injections per day. As adults, both MA groups showed no differences in swimming ability in a straight swimming channel. The MA40-4 group showed no differences in cued learning, but was impaired in hidden platform learning in the Morris water maze on acquisition. They also showed reduced memory performance on probe trials. Similar trends were seen on reversal learning and reversal probe trials. Reduced platform-size learning trials caused spatial learning impairments to re-emerge in the MA40-4 group. The MA40-2 group showed no differences in straight channel swimming, but was slower at finding the visible platform during cued learning. They were also impaired during acquisition and memory trials in the Morris hidden platform maze. They showed a similar trend on reversal learning and memory trials, but were not different during reduced platform-size learning trials. When the MA40-2 group's performance on hidden platform learning and memory trials was adjusted for cued trial performance, the spatial learning deficits remained. Deficits of spatial learning and memory are a selective effect of neonatal methamphetamine treatment irrespective of other learning and performance variables.

The Behavioral Response of Juvenile Red Snapper (Lutjanus campechanus) to Shrimp Trawls that Utilize Water Flow Modifications to Induce Escapement

Clear differences in swimming ability between finfish and shrimp in trawls have been utilized in the Southeastern U.S shrimp fishery to reduce the by catch of finfish. The Jones/Davis device which has been mandated for use in the Gulf of Mexico shrimp fishery uses four windows to provide an escape path for fish while a funnel keeps the shrimp away from the windows, reduces water flow around the windows, and acts as a leading panel to guide the fish out of the trawl. Observations of fish behavior showed that finfish generally reacted to the slack water flow created by the funnel by swimming towards the lowest water flow area. The escape rate of finfish such as juvenile red snapper (Lutjanus campechanus), however, was low and random during towing when no net surging and fish crowding occurred. The highest escape rates occurred during slow down prior to haulback, but were dependent on the haul back procedure. This may help explain the haul-to-haul variation in escapement documented for the Jones/Davis device. Modifications and techniques to improve escape rates during towing are discussed.

Temperature Effects on Swimming Performance of Larval and Juvenile Colorado Squawfish: Implications for Survival and Species Recovery

Abstract We determined prolonged swimming ability of larval and juvenile Colorado Squawfish Ptychocheilas lucius at 10, 14, and 20°C. Fatigue velocity (velocity at which 50% of the fish failed to sustain swimming in 30-min tests) increased significantly with water temperature and fish length. Differences in swimming ability between 10 and 14°C became less pronounced as fish length increased, but differences remained substantial between the two cooler and the 20°C swimming experiments for all size-classes tested. We conclude that cold hypolimnetic releases from hydroelectric dams can significantly reduce prolonged swimming ability of young-of-year Colorado Squawfish, and may help explain the decline of this species in the Colorado River basin.

Sustainable Swimming Speeds of Striped Bass Larvae

Sustainable swimming speeds, defined as speeds maintained in 1-h tests, were measured for three size-classes (6–6.9 mm, 7–7.9 mm, and 8–8.9 mm) of larval striped bass Morone saxatilis. Probit analysis was used to find failure velocities (the water velocity at which 50% of the larvae fail to sustain swimming speed) and confidence intervals for each size-class. Failure velocities were 1.7, 2.1, and 3.0 cm/s for 6–6.9-mm, 7–7.9-mm, and 8–8.9-mm larvae, respectively. There was a general improvement in swimming performance with age, There was no difference in swimming ability due to the presence or absence of an inflated swim bladder. Striped bass larvae approached the upper range of swimming speeds recorded for other larval fishes and reached speeds of 3–4 body lengths/s, which are comparable to adult fish speeds. The relatively high speeds attained by striped bass larvae may improve feeding success rates by increasing the volume of water larvae are capable of searching for food.

Swimming experiences and abilities of nine year olds.

As part of a longitudinal study of children, 941 mothers were asked to report on their childrens' swimming experiences and abilities. At age nine, twenty-nine per cent of the children could swim only a few strokes or not at all. A disproportionate number of children who could swim more than a few strokes came from high socio-economic backgrounds, from families where one or more of the parents could swim, and which scored higher on an index of active recreational orientation. There were no significant sex differences in swimming ability. There were 97 incidents reported where a child had been in difficulties while in water and had to be rescued. The importance of collecting data on such incidents is discussed.