Interactive effects of salinity on metabolic rate, activity, growth and osmoregulation in the euryhaline milkfish (Chanos chanos)

1998 ◽  
Vol 201 (24) ◽  
pp. 3355-3366
Author(s):  
C Swanson
Keyword(s):  
Metabolic Rate ◽  
High Salinity ◽  
Swimming Performance ◽  
Interactive Effects ◽  
Routine Activity ◽  
Swimming Velocity ◽  
Activity Levels ◽  
Salinity Adaptation ◽  
Chanos Chanos ◽  
Wide Range

The euryhaline milkfish (Chanos chanos) is an excellent subject for studies of the physiological and behavioral processes involved in salinity adaptation. In this study, energy partitioning for metabolism, activity and growth, maximal activity performance and blood osmotic concentrations were assessed at two activity levels in juvenile milkfish fed equal rations and maintained at a relatively constant temperature (262 C) and at salinities(15, 35 and 55 ?) that represented a wide range of osmoregulatory challenges. Changes in the measured parameters were not consistently related to the magnitude of the trans-integumentary osmotic gradients. Routine oxygen consumption rates were high in 35 ? salinity (mean 1 s.e.m. 1678 mg O2 kg-1 h-1) and comparably low in 15 and 55 ? salinity (1336 and 1273 mg O2 kg-1 h-1, respectively). Routine activity levels (relative swimming velocity) were highest in 35 ? salinity (0. 960.04 L s-1), where L is standard length, intermediate in 15 ? salinity (0.770.03 L s-1) and lowest in 55 ? salinity (0.670.03 L s-1). Growth was significantly higher in 55 ? salinity (3.40.2 % increase in wet body mass per day) than in 35 ?salinity (2.40.2 % increase per day) and intermediate in 15 ? salinity(2.90.5 % increase per day). Maximum swimming velocities decreased with increases in salinity, from 9.90.7 L s-1 in 15 ? salinity to 6.60. 5 L s-1 in 55 ? salinity. Sustained swimming activity above routine levels for 2 h resulted in an increase in blood osmotic concentrations in milkfish in 55 ?salinity, but osmoregulation was re-established during the second 2 h of activity. Thus, patterns of variation in metabolic rate and growth were largely parallel to variations in routine activity although, comparing 15 and 55 ? salinity, elevated maintenance costs for osmoregulation at the high salinity were detectable. Reduced osmoregulatory abilities and reductions in maximal swimming performance suggest that high salinity may constrain activity. The results demonstrate that investigations of salinity adaptation in euryhaline fishes should take into account the interactive effects of salinity on physiology and behavior.

Effects of fin size on swimming performance, swimming behaviour and routine activity of zebrafish Danio rerio

2000 ◽  
Vol 203 (4) ◽  
pp. 813-820 ◽  
Author(s):  
I. Plaut
Keyword(s):  
Danio Rerio ◽  
Swimming Performance ◽  
Activity Level ◽  
Routine Activity ◽  
Swimming Behaviour ◽  
Water Tunnel ◽  
Activity Levels ◽  
Wild Type ◽  
Caudal Fin ◽  
No Tail

The zebrafish Danio rerio exhibits substantial morphological variability in the sizes and shapes of the body and the caudal fin. The present study describes swimming performance, swimming behaviour and routine locomotor activity patterns in three of the major morphotypes: wild-type, long-finned and no-tail. Wild-type and long-finned differ in total length (TL), fork length (FL), caudal fin length (CFL) and caudal fin height (CFH). No-tail has no caudal fin and is significantly smaller in standard length (SL) than the other types. Critical swimming speeds (U(crit)) were measured at 28 degrees C in a modified Brett-type water tunnel. U(crit) of wild-type fish was 56.0+/−4.8 cm s(−1) or 15.5 SL s(−)(1) (mean +/− s.d., N=21), significantly faster than the U(crit) of long-finned fish (43.7+/−6.8 cm s(−1) or 12.5 SL s(−1), N=17); both were significantly faster than the U(crit) of no-tail fish (19. 8+/−4.7 cm s(−1) or 6.9 SL s(−1), N=15). When forced to swim in the water tunnel, zebrafish tended to turn and swim downstream for short periods at slow water velocities. Turning frequencies (turns per minute, f(T)) at the slowest velocity (4 cm s(−1)) were 10. 1+/−6.5 min(−)(1) (N=63) and 8.6+/−4.7 min(−1) (N=51) for wild-type and long-finned, respectively, significantly different from that of the no-tail fish, 4.7+/−2.8 min(−1) (N=45). These frequencies decreased below 1 min(−1) at 56%, 64% and 61% of U(crit) in wild-type, long-finned and no-tail fish, respectively. Activity levels of wild-type fish were generally significantly higher than those of long-finned fish, and the levels of both were significantly higher than those of no-tail fish. The pattern of differences in relative activity levels between types was similar to that for U(crit). The results show that the wild-type fish, on a size-scaled basis, is one of the fastest-swimming fishes ever measured, reaching the maximum predicted theoretical sustained swimming speed. U(crit) of long-finned fish was 22% lower than that of wild-type fish, and U(crit) of no-tail fish was 65% lower. Similar differences were found in turning frequencies and routine activity level.

The interactive effects of feeding and exercise on oxygen consumption, swimming performance and protein usage in juvenile rainbow trout (Oncorhynchus mykiss)

1997 ◽  
Vol 200 (17) ◽  
pp. 2337-2346 ◽  
Author(s):  
D Alsop ◽  
C Wood
Keyword(s):  
Rainbow Trout ◽  
Swimming Speed ◽  
Protein Intake ◽  
Swimming Performance ◽  
Circulatory System ◽  
Minor Component ◽  
Interactive Effects ◽  
Nitrogen Excretion ◽  
Swimming Velocity ◽  
Juvenile Rainbow Trout

The impacts of feeding on the rate of O2 consumption (O2), aerobic swimming performance, nitrogenous waste excretion (ammonia-N and urea-N) and protein utilization as an aerobic fuel were investigated in juvenile rainbow trout. Feeding trout to satiation (in groups of 120) resulted in rapid growth and elevated routine O2 by 68% relative to fasted fish and by 30% relative to trout fed a maintenance ration of 1% of body mass daily. This in-tank O2 of satiation-fed trout was approximately 70% of the O2max observed at the critical swimming speed (UCrit) when trials were performed on individual trout in swimming respirometers. Feeding increased O2 at all swimming speeds; the absolute elevation (specific dynamic action or SDA effect) was dependent on ration but independent of swimming velocity. There was no difference in O2max at UCrit amongst different ration treatments, but UCrit was significantly reduced by 15% in satiation-fed fish relative to fasted fish. These results suggest that the irreducible SDA load reduces swimming performance and that O2max is limited by the capacity to take up O2 at the gills and/or to deliver O2 through the circulatory system rather than by the capacity to consume O2 at the tissues. Ammonia-N and urea-N excretion increased with protein intake, resulting in a 6.5-fold elevation in absolute protein use and a fourfold elevation in percentage use of protein as an aerobic fuel for routine metabolism in satiation-fed trout (50-70%) relative to fasted fish (15%). Urea-N excretion increased greatly with swimming speed in all treatments, but remained a minor component of overall nitrogen excretion. However, even in satiation-fed fish, ammonia-N excretion remained constant as swimming speed increased, and protein did not become more important as a fuel source during exercise. These results suggest that the reliance on protein as a fuel is greatly dependent on feeding quantity (protein intake) and that protein is not a primary fuel for exercise as suggested by some previous studies.

scholarly journals Fracture risk across a wide range of physical activity levels, from sedentary individuals to elite athletes

Bone ◽  
2021 ◽  
pp. 116128
Author(s):  
Karl Stattin ◽  
Jonas Höijer ◽  
Ulf Hållmarker ◽  
John A. Baron ◽  
Susanna C. Larsson ◽  
...  
Keyword(s):  
Physical Activity ◽  
Fracture Risk ◽  
Elite Athletes ◽  
Activity Levels ◽  
Wide Range ◽  
Physical Activity Levels

Relationships Between Propulsion and Anthropometry in Paralympic Swimmers

2015 ◽  
Vol 10 (8) ◽  
pp. 978-985 ◽  
Author(s):  
Andrew A. Dingley ◽  
David B. Pyne ◽  
Brendan Burkett
Keyword(s):  
Surface Area ◽  
Muscle Mass ◽  
Physical Disability ◽  
Swimming Performance ◽  
Upper Body ◽  
Swimming Velocity ◽  
Frontal Surface ◽  
Anthropometric Measures ◽  
Arm Span ◽  
Upper Body Power

Purpose:To characterize relationships between propulsion, anthropometry, and performance in Paralympic swimming.Methods:A cross-sectional study of swimmers (13 male, 15 female) age 20.5 ± 4.4 y was conducted. Subject locomotor categorizations were no physical disability (n = 8, classes S13–S14) and low-severity (n = 11, classes S9–S10) or midseverity disability (n = 9, classes S6–S8). Full anthropometric profiles estimated muscle mass and body fat, a bilateral swim-bench ergometer quantified upper-body power production, and 100-m time trials quantified swimming performance.Results:Correlations between ergometer mean power and swimming performance increased with degree of physical disability (low-severity male r = .65, ±0.56, and female r = .68, ±0.64; midseverity, r = .87, ±0.41, and r = .79, ±0.75). The female midseverity group showed nearperfect (positive) relationships for taller swimmers’ (with a greater muscle mass and longer arm span) swimming faster, while for female no- and low-severity-disability groups, greater muscle mass was associated with slower velocity (r = .78, ±0.43, and r = .65, ±0.66). This was supported with lighter females (with less frontal surface area) in the low-severity group being faster (r = .94, ±0.24). In a gender contrast, low-severity males with less muscle mass (r = -.64, ±0.56), high skinfolds (r = .78, ±0.43), a longer arm span (r = .58, ±0.60) or smaller frontal surface area (r = -.93, ±0.19) were detrimental to swimming-velocity production.Conclusion:Low-severity male and midseverity female Paralympic swimmers should be encouraged to develop muscle mass and upper-body power to enhance swimming performance. The generalized anthropometric measures appear to be a secondary consideration for coaches.

Metabolic Rate and Energy Expenditure of the Spiny Dogfish, Squalus acanthias

1978 ◽  
Vol 35 (6) ◽  
pp. 816-821 ◽  
Author(s):  
J. R. Brett ◽  
J. M. Blackburn
Keyword(s):  
Energy Expenditure ◽  
Metabolic Rate ◽  
Key Words ◽  
Swimming Performance ◽  
Squalus Acanthias ◽  
Spiny Dogfish ◽  
Metabolic Rates ◽  
Performance Curve ◽  
Power Performance ◽  
General Energy

The metabolic rate of spiny dogfish, Squalus acanthias, was determined in both a tunnel respirometer and a large, covered, circular tank (mass respirometer). Swimming performance was very poor in the respirometer, so that a power–performance curve could not be established. Instead, resting metabolic rates were determined, with higher rates induced by causing heavy thrashing (active metabolism). Routine metabolic rates were measured for the spontaneous activity characterizing behavior in the circular tank. For fish of 2 kg mean weight, the metabolic rates at 10 °C were 32.4 ± 2.6 SE (resting), 49.2 ± 5.0 SE (routine), and 88.4 ± 4.6 SE (active) mg O2∙kg−1∙h−1. Assuming that the routine rate represents a general energy expenditure in nature, this is equivalent to metabolizing about 3.8 kcal∙kg−1∙d−1 (15.9 × 103 J∙kg−1∙d−1). Key words: dogfish, metabolic rates, energetics, respiration

scholarly journals Metagenomic Signatures of Bacterial Adaptation to Life in the Phyllosphere of a Salt-Secreting Desert Tree

2016 ◽  
Vol 82 (9) ◽  
pp. 2854-2861 ◽  
Author(s):  
Omri M. Finkel ◽  
Tom O. Delmont ◽  
Anton F. Post ◽  
Shimshon Belkin
Keyword(s):  
High Salinity ◽  
Stress Factors ◽  
Metagenomic Data ◽  
Metagenomic Sequencing ◽  
Contig Assembly ◽  
Bacterial Populations ◽  
Content Type ◽  
Light Sensing ◽  
Wide Range ◽  
Globally Distributed

ABSTRACTThe leaves ofTamarix aphylla, a globally distributed, salt-secreting desert tree, are dotted with alkaline droplets of high salinity. To successfully inhabit these organic carbon-rich droplets, bacteria need to be adapted to multiple stress factors, including high salinity, high alkalinity, high UV radiation, and periodic desiccation. To identify genes that are important for survival in this harsh habitat, microbial community DNA was extracted from the leaf surfaces of 10Tamarix aphyllatrees along a 350-km longitudinal gradient. Shotgun metagenomic sequencing, contig assembly, and binning yielded 17 genome bins, six of which were >80% complete. These genomic bins, representing three phyla (Proteobacteria,Bacteroidetes, andFirmicutes), were closely related to halophilic and alkaliphilic taxa isolated from aquatic and soil environments. Comparison of these genomic bins to the genomes of their closest relatives revealed functional traits characteristic of bacterial populations inhabiting theTamarixphyllosphere, independent of their taxonomic affiliation. These functions, most notably light-sensing genes, are postulated to represent important adaptations toward colonization of this habitat.IMPORTANCEPlant leaves are an extensive and diverse microbial habitat, forming the main interface between solar energy and the terrestrial biosphere. There are hundreds of thousands of plant species in the world, exhibiting a wide range of morphologies, leaf surface chemistries, and ecological ranges. In order to understand the core adaptations of microorganisms to this habitat, it is important to diversify the type of leaves that are studied. This study provides an analysis of the genomic content of the most abundant bacterial inhabitants of the globally distributed, salt-secreting desert treeTamarix aphylla. Draft genomes of these bacteria were assembled, using the culture-independent technique of assembly and binning of metagenomic data. Analysis of the genomes reveals traits that are important for survival in this habitat, most notably, light-sensing and light utilization genes.

The interactive effects of stream temperature, stream size, and non-native species on Yellowstone cutthroat trout

2021 ◽  
Author(s):  
Robert Al-Chokhachy ◽  
Mike Lien ◽  
Bradley B. Shepard ◽  
Brett High
Keyword(s):  
Native Species ◽  
Cutthroat Trout ◽  
Population Level ◽  
Stream Temperature ◽  
Interactive Effects ◽  
Oncorhynchus Clarkii ◽  
Wide Range ◽  
Yellowstone Cutthroat Trout ◽  
Stream Size ◽  
Native Salmonids

Climate change and non-native species are considered two of the biggest threats to native salmonids in North America. We evaluated how non-native salmonids and stream temperature and discharge were associated with Yellowstone cutthroat trout (Oncorhynchus clarkii bouvieri) distribution, abundance, and body size, to gain a more complete understanding of the existing threats to native populations. Allopatric Yellowstone cutthroat trout were distributed across a wide range of average August temperatures (3.2 to 17.7ºC), but occurrence significantly declined at colder temperatures (<10 ºC) with increasing numbers of non-natives. At warmer temperatures occurrence remained high, despite sympatry with non-natives. Yellowstone cutthroat trout relative abundance was significantly reduced with increasing abundance of non-natives, with the greatest impacts at colder temperatures. Body sizes of large Yellowstone cutthroat trout (90th percentile) significantly increased with warming temperatures and larger stream size, highlighting the importance of access to these more productive stream segments. Considering multiple population-level attributes demonstrates the complexities of how native salmonids (such as Yellowstone cutthroat trout) are likely to be affected by shifting climates.

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