Effects of acclimation to brackish water on tolerance of salinity challenge by young-of-the-year Adriatic sturgeon (Acipenser naccarii)

2001 ◽  
Vol 58 (6) ◽  
pp. 1113-1121 ◽  
Author(s):  
D J McKenzie ◽  
E Cataldi ◽  
P Romano ◽  
E W Taylor ◽  
S Cataudella ◽  
...  
Keyword(s):  
Oxygen Uptake ◽  
Linear Relationship ◽  
Swimming Speed ◽  
Brackish Water ◽  
Swimming Performance ◽  
Ion Homeostasis ◽  
Plasma Osmolality ◽  
Young Of The Year ◽  
Salinity Challenge ◽  
Negative Linear Relationship

The effects of a 24-h salinity challenge in water at 28 g·L–1 on plasma osmotic and ion homeostasis, swimming performance, and exercise respirometry were compared in young-of-the-year Adriatic sturgeon (Acipenser naccarii) maintained in freshwater (FW) or acclimated to brackish water (BW) that was slightly hypertonic to sturgeon plasma at a salinity of 11 g·L–1. Salinity challenge caused a significant increase in plasma osmolality and Na+ and Cl– concentrations in both groups, but this was significantly less severe in the group acclimated to the BW as compared with FW. Salinity challenge elicited a significant and profound decline in maximum sustainable swimming speed (Ucrit) in sturgeon from FW, whereas there was no significant effect on Ucrit in the sturgeon acclimated to BW. A negative linear relationship was revealed between plasma osmolality, Na+ or Cl– concentrations, and Ucrit. These variables appeared to influence Ucrit by increasing costs for locomotion while reducing the sturgeon's capacity for oxygen uptake and muscular work. The results indicate that prior acclimation to mildly hypertonic BW promoted osmoregulatory adaptations that improved the ability of the sturgeon to perform exercise following further increases in water salinity.

Effects of acclimation to brackish water on the growth, respiratory metabolism, and swimming performance of young-of-the-year Adriatic sturgeon (Acipenser naccarii)

2001 ◽  
Vol 58 (6) ◽  
pp. 1104-1112 ◽  
Author(s):  
D J McKenzie ◽  
E Cataldi ◽  
P Romano ◽  
S F Owen ◽  
E W Taylor ◽  
...  
Keyword(s):  
Oxygen Uptake ◽  
Metabolic Rate ◽  
Swimming Speed ◽  
Brackish Water ◽  
Specific Growth ◽  
Swimming Performance ◽  
Standard Metabolic Rate ◽  
Power Relationship ◽  
Young Of The Year ◽  
Specific Growth Rates

Specific growth rates, exercise respirometry, and swimming performance were compared in young-of-the-year Adriatic sturgeon (Acipenser naccarii) maintained in freshwater (FW) or acclimated to brackish water (BW) that was slightly hypertonic to sturgeon plasma, at a salinity of 11 g·L–1. Specific growth rate was significantly (17%) lower in BW than in FW. Sturgeon in BW also had a significantly (30%) higher standard metabolic rate than those in FW. In both groups, the relationship between swimming speed and oxygen uptake was described equally well by a linear or exponential equation, with a power relationship between swimming speed and net cost of locomotion and a linear relationship between tailbeat frequency and swimming speed. However, sturgeon in BW exhibited higher mean total oxygen uptake, net costs, and tailbeat frequencies than the FW group at any given swimming speed. There were, however, no differences in aerobic scope or maximum sustainable swimming speed between the FW and BW groups because the BW group exhibited a compensatory increase in active metabolic rate and maximum tailbeat frequency. The results indicate that FW is a more suitable environment than mildly hypertonic BW for young-of-the-year Adriatic sturgeon.

Influence of Light on Fruit Set of French Hybrid Grapes

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 510f-511 ◽  
Author(s):  
D.C. Ferree ◽  
S.J. McArtney ◽  
D.M. Scurlock
Keyword(s):  
Light Intensity ◽  
Linear Relationship ◽  
Fruit Set ◽  
Light Level ◽  
Fruit Color ◽  
Soluble Solids ◽  
Hue Angle ◽  
Reduced Light ◽  
Negative Linear Relationship ◽  
Grape Cultivars

Four French–American hybrid grape cultivars grown in a greenhouse were subjected to 5 days of 80% shade at four different times around bloom. Fruit set of `Seyval' was reduced by shade imposed before, during, or immediately after bloom. `Vidal' and `Chambourcin' were less sensitive, with fruit set reduced only by shade at bloom. Shade had little effect on fruit set of `DeChaunac'. In a second study, `Chambourcin' vines were exposed to ambient, ambient plus supplemental lights, and 30%, 50%, or 80% shade for 5 weeks beginning just prior to bloom. Fruit set was positively related to light intensity. At harvest, soluble solids, pH, and hue angle had a negative linear relationship to light level. Fruit color developed earliest and most rapidly with the reduced light treatments applied at bloom. Cluster weight was positively related to light intensity.

Impact of Diet on Metabolism and Swimming Performance in Juvenile Lake Trout, Salvelinus namaycush

1989 ◽  
Vol 46 (3) ◽  
pp. 384-388 ◽  
Author(s):  
F. W. H. Beamish ◽  
J. C. Howlett ◽  
T. E. Medland
Keyword(s):  
Oxygen Consumption ◽  
Swimming Speed ◽  
Lake Trout ◽  
Swimming Performance ◽  
Salvelinus Namaycush ◽  
Feeding Trial ◽  
Direct Association ◽  
Feeding Trials ◽  
Velocity Increments ◽  
Isocaloric Diets

Juvenile lake trout, Salvelinus namaycush, of similar size were fed one of three isocaloric diets, each differing in protein and lipid content. Oxygen consumption and swimming performance were measured in a recirculating water flume at intervals throughout the 70-d feeding trials (10 °C). Swimming speed was increased by stepwise velocity increments (5 cm∙s−1) and oxygen consumption was measured at each velocity between 20 and 45 cm∙s−1. Oxygen consumption for a given speed did not differ significantly throughout the feeding trial nor among the diets implying a similarity in the quality and quantity of substrate catabolized for energy. Basal metabolism (0 cm∙s−1) was also independent of diet and feeding interval. Critical swimming speed increased with dietary and carcass protein content to suggest a direct association with muscle mass and number of myofilaments.

scholarly journals Feeding strategy of mackerel in the Norwegian Sea relative to currents, temperature, and prey

2015 ◽  
Vol 73 (4) ◽  
pp. 1127-1137 ◽  
Author(s):  
Leif Nøttestad ◽  
Justine Diaz ◽  
Hector Penã ◽  
Henrik Søiland ◽  
Geir Huse ◽  
...  
Keyword(s):  
Swimming Speed ◽  
Swimming Performance ◽  
Feeding Strategy ◽  
Near Field ◽  
Norwegian Sea ◽  
Swimming Direction ◽  
Atlantic Mackerel ◽  
The North ◽  
Foraging Rate ◽  
Feeding Resources

Abstract High abundance of Northeast Atlantic mackerel (Scomber scombrus L.), combined with limited food resources, may now force mackerel to enter new and productive regions in the northern Norwegian Sea. However, it is not known how mackerel exploit the spatially varying feeding resources, and their vertical distribution and swimming behaviour are also largely unknown. During an ecosystem survey in the Norwegian Sea during the summer feeding season, swimming direction, and speed of mackerel schools were recorded with high-frequency omnidirectional sonar in four different regions relative to currents, ambient temperature, and zooplankton. A total of 251 schools were tracked, and fish and zooplankton were sampled with pelagic trawl and WP-2 plankton net. Except for the southwest region, swimming direction of the tracked schools coincided with the prevailing northerly Atlantic current direction in the Norwegian Sea. Swimming with the current saves energy, and the current also provides a directional cue towards the most productive areas in the northern Norwegian Sea. Average mean swimming speed in all regions combined was ∼3.8 body lengths s−1. However, fish did not swim in a straight course, but often changed direction, suggesting active feeding in the near field. Fish were largest and swimming speed lowest in the northwest region which had the highest plankton concentrations and lowest temperature. Mackerel swam close to the surface at a depth of 8–39 m, with all schools staying above the thermocline in waters of at least 6°C. In surface waters, mackerel encounter improved foraging rate and swimming performance. Going with the flow until temperature is too low, based on an expectation of increasing foraging rate towards the north while utilizing available prey under way, could be a simple and robust feeding strategy for mackerel in the Norwegian Sea.

THE EFFECT OF SOLID AND POROUS CHANNEL WALLS ON STEADY SWIMMING OF STEELHEAD TROUT ONCORHYNCHUS MYKISS

1993 ◽  
Vol 178 (1) ◽  
pp. 97-108 ◽  
Author(s):  
P. W. Webb
Keyword(s):  
Swimming Speed ◽  
Swimming Performance ◽  
Beat Frequency ◽  
Regression Coefficients ◽  
Steelhead Trout ◽  
Wall Effects ◽  
Fish Swimming ◽  
Wide Channel ◽  
Solid Walls ◽  
Tail Beat

Kinematics and steady swimming performance were recorded for steelhead trout (approximately 12.2 cm in total length) swimming in channels 4.5, 3 and 1.6 cm wide in the centre of a flume 15 cm wide. Channel walls were solid or porous. Tail-beat depth and the length of the propulsive wave were not affected by spacing of either solid or porous walls. The product of tail-beat frequency, F, and amplitude, H, was related to swimming speed, u, and to harmonic mean distance of the tail from the wall, z. For solid walls: FH = 1.01(+/−0.31)u0.67(+/−0.09)z(0.12+/−0.02) and for grid walls: FH = 0.873(+/−0.302)u0.74(+/−0.08)z0.064(+/−0.024), where +/−2 s.e. are shown for regression coefficients. Thus, rates of working were smaller for fish swimming between solid walls, but the reduction due to wall effects decreased with increasing swimming speed. Porous grid walls had less effect on kinematics, except at low swimming speeds. Spacing of solid walls did not affect maximum tail-beat frequency, but maximum tail-beat amplitude decreased with smaller wall widths. Maximum tail-beat amplitude similarly decreased with spacing between grid walls, but maximum tail-beat frequency increased. Walls also reduced maximum swimming speed. Wall effects have not been adequately taken into account in most studies of fish swimming in flumes and fish wheels.

scholarly journals The Maximal Lactate Steady State Workload Determines Individual Swimming Performance

2021 ◽  
Vol 12 ◽  
Author(s):  
Gernot O. Hering ◽  
Jens Stepan
Keyword(s):  
Steady State ◽  
Blood Lactate ◽  
Swimming Speed ◽  
Lactate Threshold ◽  
Swimming Performance ◽  
Endurance Capacity ◽  
Sudden Increase ◽  
Maximal Lactate Steady State ◽  
Custom Made ◽  
Major Interest

The lactate threshold (LT) and the strongly related maximal lactate steady state workload (MLSSW) are critical for physical endurance capacity and therefore of major interest in numerous sports. However, their relevance to individual swimming performance is not well understood. We used a custom-made visual light pacer for real-time speed modulation during front crawl to determine the LT and MLSSW in a single-exercise test. When approaching the LT, we found that minute variations in swimming speed had considerable effects on blood lactate concentration ([La−]). The LT was characterized by a sudden increase in [La−], while the MLSSW occurred after a subsequent workload reduction, as indicated by a rapid cessation of blood lactate accumulation. Determination of the MLSSW by this so-called “individual lactate threshold” (ILT)-test was highly reproducible and valid in a constant speed test. Mean swimming speed in 800 and 1,500 m competition (S-Comp) was 3.4% above MLSSW level and S-Comp, and the difference between S-Comp and the MLSSW (Δ S-Comp/MLSSW) were higher for long-distance swimmers (800–1,500 m) than for short- and middle-distance swimmers (50–400 m). Moreover, Δ S-Comp/MLSSW varied significantly between subjects and had a strong influence on overall swimming performance. Our results demonstrate that the MLSSW determines individual swimming performance, reflects endurance capacity in the sub- to supra-threshold range, and is therefore appropriate to adjust training intensity in moderate to severe domains of exercise.

scholarly journals In maintenance hemodialysis patients, there were “U-shaped” relationships between serum albumin level and mortality or hospitalization, negative linear relationship between serum albumin level and hospitalization for infection.

2019 ◽  
Author(s):  
Xiaoyan Jia ◽  
Ping Chen ◽  
Xue Wang ◽  
Xianglei Kong ◽  
Juan Chen ◽  
...  
Keyword(s):  
Serum Albumin ◽  
Cerebrovascular Disease ◽  
Linear Relationship ◽  
Serum Albumin Level ◽  
Cox Regression ◽  
Albumin Level ◽  
Maintenance Hemodialysis ◽  
Linear Association ◽  
Non Linear ◽  
Negative Linear Relationship

Abstract Background: Few studies are available on the non-linear association between serum albumin (S-Alb) level and prognosis in maintenance hemodialysis (MHD) patients. Methods: All stable MHD patients treated in our center from 2007 to 2011 were enrolled into this study. Demographics, laboratory data, hospitalization and mortality were collected; Cox regressive models were fitted to investigate predicting outcomes, restricted cubic splines (RCS) were allowing for non-linear association between S-Alb and prognosis. Results: S-Alb was independent protective factor for mortality, all-cause hospitalization, hospitalization for cardiovascular or cerebrovascular disease and hospitalization for infection. The relationships between S-Alb and mortality, all-cause hospitalization, hospitalization for cardiovascular or cerebrovascular disease were U-shaped; relationships between S-Alb and hospitalization for infection were negative linear relationships both in univariable Cox regression models and in multivariable Cox regression. Conclusions: In MHD population, there were “U-shaped” relationships between serum albumin level and mortality or hospitalization; the potential risks associated with excessive S-Alb should been taken into consideration. There was negative linear relationship between S-Alb and hospitalization for infection, S-Alb may be even more important in preventing infection in MHD population.

THE IN VITRO ACTION OF ACTH ON THE OXYGEN CONSUMPTION OF SLICES OF CATTLE ADRENAL CORTEX

1953 ◽  
Vol 9 (4) ◽  
pp. 379-390 ◽  
Author(s):  
M. REISS ◽  
EVA BRUMMEL ◽  
I. D. K. HALKERSTON ◽  
F. E. BADRICK ◽  
M. FENWICK
Keyword(s):  
Oxygen Consumption ◽  
Oxygen Uptake ◽  
Linear Relationship ◽  
Adrenal Cortex ◽  
Oxygen Consumption Rate ◽  
Consumption Rate ◽  
Biological Assay ◽  
Percentage Increase ◽  
Small Doses

A technique for measuring the action of small doses of ACTH on the oxygen consumption of slices of cattle adrenal cortex is described. The oxygen consumption rate of such slices in vitro is increased by ACTH. A linear relationship between logarithm of the dose of ACTH and the percentage increase in the rate of oxygen uptake is obtained with this method, and its suitability for biological assay purposes has been investigated. The question of the specificity of this action of ACTH is discussed.

Effect of Morphological Fin-Curl on the Swimming Performance and Station-Holding Ability of Juvenile Shovelnose Sturgeon

2016 ◽  
Vol 7 (1) ◽  
pp. 198-204 ◽  
Author(s):  
David Deslauriers ◽  
Ryan Johnston ◽  
Steven R. Chipps
Keyword(s):  
Swimming Speed ◽  
Early Onset ◽  
Positive Relationship ◽  
Swimming Performance ◽  
Fork Length ◽  
Critical Swimming Speed ◽  
Pectoral Fin ◽  
Speed Test ◽  
Shovelnose Sturgeon ◽  
Pectoral Fins

Abstract We assessed the effect of fin-curl on the swimming and station-holding ability of juvenile shovelnose sturgeon Scaphirhynchus platorynchus (mean fork length = 17 cm; mean weight = 16 g; n = 21) using a critical swimming speed test performed in a small swim chamber (90 L) at 20°C. We quantified fin-curl severity using the pectoral fin index. Results showed a positive relationship between pectoral fin index and critical swimming speed indicative of reduced swimming performance displayed by fish afflicted with a pectoral fin index < 8%. Fin-curl severity, however, did not affect the station-holding ability of individual fish. Rather, fish affected with severe fin-curl were likely unable to use their pectoral fins to position their body adequately in the water column, which led to the early onset of fatigue. Results generated from this study should serve as an important consideration for future stocking practices.

Cercarial swimming performance and its potential role as a key variable of trematode transmission

Parasitology ◽  
2020 ◽  
Vol 147 (12) ◽  
pp. 1369-1374 ◽  
Author(s):  
Neil J. Morley
Keyword(s):  
Swimming Speed ◽  
Potential Role ◽  
Swimming Performance ◽  
Tail Length ◽  
Host Searching ◽  
Aquatic Habitats ◽  
Searching Behaviour ◽  
Biological Variables ◽  
Using Data

AbstractTrematode transmission in aquatic habitats from molluscan intermediate host to vertebrate or invertebrate target host is typically undertaken by a free-living stage known as cercariae. Active locomotion by cercariae is a key aspect of the transmission process with the swimming speed potentially contributing to infection success. Individual cercarial species swim at different speeds but the significance of this to infection potential has not been determined. This study, using data from the scientific literature, investigates the role of swimming speed in relation to cercarial morphology, host-searching strategies and target host species. Larger cercariae swim faster than smaller ones with tail length being the principal factor controlling locomotion rates. Different cercarial morphotypes swim at different speeds, in particular, furcocercariae, with the exception of the schistosomes, being faster swimmers than mono-tailed cercariae. Host-searching behaviour has a significant influence on swimming speeds with ‘active-searching’ strategies swimming slower than those adopting ‘active-waiting’ or ‘prey mimcry’ strategies. Vertebrate-infecting cercariae swim faster than those infecting invertebrates with species targeting fish demonstrating the highest locomotion rates and those targeting arthropods the slowest speeds. The adaptions of individual cercarial swimming speeds to biological variables and their interactions with the physical processes of aquatic habitats are discussed.

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