A Mathematical Model of Some Aspects of Fish Growth, Respiration, and Mortality

1967 ◽  
Vol 24 (11) ◽  
pp. 2355-2453 ◽  
Author(s):  
Erik Ursin
Keyword(s):  
Mathematical Model ◽  
Weight Loss ◽  
Oxygen Consumption ◽  
Metabolic Model ◽  
The Body ◽  
Fish Growth ◽  
Natural Mortality ◽  
Gill Area ◽  
Growth Respiration ◽  
The Difference

A simple metabolic model describing growth as the difference between what enters the body and what leaves it, is elaborated assuming that synthetic processes (the building-up, the anabolism) are consuming energy supplied by processes of decomposition (the break-down, the catabolism). This leads to partitioning total catabolism into two components, one being a function of the rate of synthesis, another keeping the body functioning independently of synthesis. The rate of synthesis is described as a function of food taken, of the efficiencies of digestion and energy conversion, and of the absorbing surface of the intestine. Catabolic processes are supposed to be functions of the oxygen concentration in the water, the absorbing surface of the gills, and the rate of oxygen transport. Both kinds of processes are made functions of temperature in the way enzymatic processes usually are. Assuming that molecular interactions accidentally go wrong makes natural mortality, like growth, a function of the rates of anabolic and catabolic processes and body size.Application of the model to data of length-at-age, food and oxygen consumption, weight loss, gill area, and natural mortality indicates that at least some of the main hypotheses cannot be rejected on available evidence.

scholarly journals Mathematical model for predicting oxygen concentration in tilapia fish farms

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
El-Sayed Khater ◽  
Adel Bahnasawy ◽  
Hossam El-Ghobashy ◽  
Yousry Shaban ◽  
Faisal Elsheikh ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Oxygen Consumption ◽  
Dissolved Oxygen ◽  
Growth Period ◽  
Fish Growth ◽  
Fish Farms ◽  
Recirculating Aquaculture ◽  
Oxygen Generator ◽  
Oxygen Addition ◽  
The Individual

AbstractThe main aim of this research is to develop a mathematical model to predict the dissolved oxygen in recirculating aquaculture system. The oxygen consumption of the model through the fish respiration and nitrification and the oxygen addition of the model through oxygen generator and water pumping. The effect of different water temperatures (24, 26, 28, 30 and 32 °C) on the dissolved oxygen consumption through fish respiration, biofilter and nitrification and fish growth were studied. An experiment to measure oxygen consumed by fish respiration and biofilteration and fish growth with the growth period and to validate the model results was carried out. The oxygen consumption predicted by the model was in a good agreement with those measured by the system. The oxygen consumption by fish respiration ranged 12.04 to 47.53 g O2 m−3 h−1 experimentally, while it was from 12.01 to 46.06 g O2 m−3 h−1 theoretically. The predicted and measured oxygen consumption through biofilteration values ranged from 0.43 to 21.91 and 0.45 to 23.09 g O2 m−3 h−1, respectively. The individual fish weight from the system ranged from 3.00 to 209.52 g experimentally while it was from 3.00 to 226.25 g theoretically during the whole period.

The Swimming Energetics of Trout

1971 ◽  
Vol 55 (2) ◽  
pp. 521-540 ◽  
Author(s):  
P. W. WEBB
Keyword(s):  
Oxygen Consumption ◽  
Swimming Speed ◽  
Swimming Performance ◽  
The Body ◽  
Control Group ◽  
Muscle System ◽  
Rate Of Oxygen Consumption ◽  
Wet Weight ◽  
Standard Rate ◽  
The Difference

1. The oxygen consumption of rainbow trout was measured at a variety of subfatigue swimming speeds, at a temperature of 15 %C. Five groups of fish were used, a control group and four groups with extra drag loads attached to the body. 2. The logarithm of oxygen consumption was linearly related to swimming speed in all five groups, the slope of the relationship increasing with the size of the extra drag load. The mean standard rate of oxygen consumption was 72.5 mg O2/kg wet weight/h. The active rate of oxygen consumption was highest for the control group (628 mg O2/kg/h) and fell with increasing size of the attached drag load. The active rate for the control group was high in comparison with other salmonid fish, and in comparison with the value expected for the fish. This was not a result of the extra drag loads in the other groups. No explanation for this high value can be found. 3. The critical swimming speed for a 60 min test period was 58.1 cm/sec (2.0 body lengths/sec) for the control group. The values for the critical swimming speeds were slightly higher than those measured for the same species in a previous paper (Webb, 1971). The difference between the two sets of critical swimming speeds is attributed to seasonal changes in swimming performance. 4. The aerobic efficiency was found to reach values of 14.5-15.5% based on the energy released by aerobic metabolism in comparison with the calculated required thrust. 5. The anaerobic contribution to the total energy budget in increasing-velocity tests is considered to be small, and can be neglected. 6. It is concluded that the efficiency of the muscle system in cruising will be approximately 17-20% over the upper 80% of the cruising-speed range, while the caudal propeller efficiency will increase from about 15-75 % over the same range. 7. Consideration of the efficiency values for the caudal propeller calculated here, and those predicted by Lighthill's (1969) model of fish propulsion, suggest that the efficiency of the propeller system will reach an optimum value at the maximum cruising speeds of most fish, and will remain close to this value at spring speeds.

Energetics of Sablefish, Anoplopoma fimbria, under Laboratory Conditions

1982 ◽  
Vol 39 (7) ◽  
pp. 1012-1020 ◽  
Author(s):  
Kathleen M. Sullivan ◽  
Kenneth L. Smith Jr.
Keyword(s):  
Body Weight ◽  
Oxygen Consumption ◽  
Growth Rates ◽  
The Body ◽  
Fish Growth ◽  
Metabolic Rates ◽  
Anoplopoma Fimbria ◽  
Consumption Rates ◽  
Excretion Rates ◽  
Conversion Efficiencies

We measured respiration, growth, ingestion, and excretion rates for sablefish, Anoplopoma fimbria, collected off southern California at a depth of 500 m and maintained in the laboratory. We also measured the water, protein, and lipid content of white skeletal muscle in both laboratory-held and field fish. Sablefish fed a large ration (14% of wet body weight) every 7–10 d showed growth rates two to three times higher than known growth rates for field fish. On a reduced ration (4% of wet body weight) sablefish grew at rates similar to field fish, but white muscle composition varied significantly from field fish. Oxygen consumption rates under constant temperature conditions showed a decrease in the weight-specific oxygen consumption rates with increase in body weight, ranging from routine metabolic rates of 195.8 mg O2∙kg−1∙h−1 for a 0.25-kg fish to 60.8 mg O2∙kg−1∙h−1 for a 2.78-kg fish. Based on measurements of respiration and excretion, sablefish were estimated to have 162 d of energy stored in the body lipids and did not show signs of starvation stress with food deprivation up to 6 mo in the laboratory. Energy allocation shows very slow growth rates, low conversion efficiencies, and low metabolic rates as adjustments made to large, infrequent meals.Key words: physiological responses, benthopelagic fish, growth, metabolic rate, respiration, excretion

INFLUENCE OF VARIATION IN ENVIRONMENTAL TEMPERATURE ON THE ACUTE TOXICITY OF RESERPINE AND CHLORPROMAZINE IN MICE

1960 ◽  
Vol 38 (1) ◽  
pp. 591-596 ◽  
Author(s):  
P. C. Dandiya ◽  
Gordon Johnson ◽  
E. A. Sellers
Keyword(s):  
Oxygen Consumption ◽  
Acute Toxicity ◽  
Environmental Temperature ◽  
Mechanisms Of Action ◽  
The Body ◽  
Time Of Death ◽  
Rapid Loss ◽  
Higher Temperature ◽  
The Difference ◽  
Maintain Body Temperature

The acute toxicity of chlorpromazine in mice is 18 times higher in an environment of 4 °C than in a thermoneutral environment of 30 °C. Under similar conditions the acute toxicity of reserpine increases about 1200 times. These findings confirm the earlier suggestion that these drugs cause hypothermia by different mechanisms of action. Increased acute toxicity of these drugs was also noticed at a higher temperature (36 °C).At 4 °C, after chlorpromazine, death occurred earlier than after reserpine. Reserpine produced a transient increase in oxygen consumption (in rats) which helped maintain body temperature but resulted in a more rapid loss of heat from the body. This would explain the difference in time of death and might explain the difference in ultimate mortality between the animals treated with these two drugs.

Molting and Respiration of Euphausiids

1967 ◽  
Vol 24 (6) ◽  
pp. 1229-1240 ◽  
Author(s):  
Madhu A. Paranjape
Keyword(s):  
Body Weight ◽  
Oxygen Consumption ◽  
Dry Weight ◽  
Temperature Tolerance ◽  
The Body ◽  
Organic Fraction ◽  
Temperature Relation ◽  
Increase With Increase ◽  
Daily Food ◽  
The Difference

Euphausia pacifica, Thysanoëssa spinifera, T. raschii, T. longipes (unspined form), and Tessarabrachion oculatus molted at 4- to 6-day intervals at 11 to 15 C. The average dry weight of the molts of the first three species was 5.92–9.39% of the animal's final dry weight, and the organic fraction ranged from 73 to 83% of the dry weight of the molts. The oxygen consumption of E. pacifica at 5, 10, 15, and 20 C was directly proportional to the body weight. The slopes of the regression lines were near unity at all temperatures and the difference between the regression coefficients was not significant statistically. The respiration–temperature relation of E. pacifica suggested its eurythermic character. The Q10 value was 2.21 between 5 and 10 C and increased to 2.55 between 10 and 15 C. The Q10 value apparently did not increase with increase in body size. The upper limit of temperature tolerance for the observed population of E. pacifica was close to 20 C. On the day of molting, oxygen consumption of E. pacifica increased by an average of 34.2%. Feeding decreased on the day before and on the day of molting and increased after molting. At 15 C, a daily food intake of 0.022 mg carbon per milligram dry body weight would be required to match the respiratory loss and the loss of integument during the molt.

scholarly journals A MATHEMATICAL MODEL OF GALVANIC CORROSION UNDER THE CONDITIONS OF A THIN ELECTROLYTE FILM

2016 ◽  
Vol 56 (2) ◽  
pp. 106-111
Author(s):  
Vít Jeníček ◽  
Linda Diblíková
Keyword(s):  
Mathematical Model ◽  
Weight Loss ◽  
Time Dependence ◽  
Experimental Error ◽  
Atmospheric Corrosion ◽  
Galvanic Corrosion ◽  
Experimental Results ◽  
Polarization Curves ◽  
Electrolyte Film ◽  
The Difference

<p>A mathematical model of galvanic corrosion under the conditions of a thin electrolyte film was used to evaluate atmospheric corrosion. Experimentally determined weight loss values were used to validate the modelled results. The time dependence of the corrosion degradation was included in the model using polarization curves of the corroded materials. The difference between the modelled results and the experimental results was 20%, taking the experimental error into account.</p>

Temperature dependence and ontogenetic changes of metabolic rate of an endemic earthworm Dendrobaena mrazeki

Biologia ◽  
2010 ◽  
Vol 65 (2) ◽  
Author(s):  
Vladimír Šustr ◽  
Václav Pižl
Keyword(s):  
Oxygen Consumption ◽  
Metabolic Rate ◽  
Temperature Dependence ◽  
Respiration Rate ◽  
Temperature Response ◽  
The Body ◽  
Ontogenetic Changes ◽  
Earthworm Species ◽  
Lethal Limit ◽  
The Difference

AbstractOntogenetic changes and temperature dependency of respiration rate were studied in Dendrobaena mrazeki, an earthworm species inhabiting relatively warm and dry habitats in Central Europe. D. mrazeki showed respiration rate lower than in other earthworm species, < 70 μl O2 g−1 h−1, within the temperature range of 5–35°C. The difference of respiration rate between juveniles and adults was insignificant at 20°C. The response of oxygen consumption to sudden temperature changes was compared with the temperature dependence of respiratory activity in animals pre-acclimated to temperature of measurement. No significant impact of acclimation on the temperature response of oxygen consumption was found. The body mass-adjusted respiration rate increased slowly with increasing temperature from 5 to 25°C (Q10 from 1.2 to 1.7) independently on acclimation history of earthworms. Oxygen consumption decreased above 25°C up to upper lethal limit (about 35°C). Temperature dependence of metabolic rate is smaller than in other earthworm species. The relationships between low metabolic sensitivity to temperature, slow locomotion and reactivity to touching as observed in this species are discussed.

scholarly journals ANALYZING GAIT USING THE DYNAMICS OF A MATHEMATICAL MODEL?

2019 ◽  
Vol 4 (1) ◽  
pp. 45-56
Author(s):  
Hashem KILANI ◽  
Manfred Vieten
Keyword(s):  
Dynamical System ◽  
Mathematical Model ◽  
Computer Simulation ◽  
System Approach ◽  
The Body ◽  
Student Group ◽  
Normal Gait ◽  
Modern Development ◽  
The Difference ◽  
In The Beginning

Athletes need modeling and feedback to reach for their maximum performance, computer simulation is not the only nontraditional modern development in biomechanics. Dynamical system approach (DSA) is another fascinating enlargement in the field of biomechanics.   The purpose of this study was to investigate the practicability of this assessment by showing the dynamics of the movement and the differences in movement patterns by comparing the frequency patterns of the gait of the different subject groups.   Three different groups were examined in this study. These groups were: control patient group (CP), senior group (S), and sport student group (SS). The CP-group was composed of (9)patients ,the S-group and the SS-group had no neurophysiological diseases and were composed of 17 senior.   Results showed that the S-group and the SS-group resembled patterns and data with the difference of higher peaks at the beginning and a higher gradient between the first peaks for the seniors. The CP-group shows much lower peaks in the beginning and higher peak values to the end, also the differences between both sides of the body are obvious in comparison to the normal gait of the SS-group.

INFLUENCE OF VARIATION IN ENVIRONMENTAL TEMPERATURE ON THE ACUTE TOXICITY OF RESERPINE AND CHLORPROMAZINE IN MICE

1960 ◽  
Vol 38 (6) ◽  
pp. 591-596 ◽  
Author(s):  
P. C. Dandiya ◽  
Gordon Johnson ◽  
E. A. Sellers
Keyword(s):  
Oxygen Consumption ◽  
Acute Toxicity ◽  
Environmental Temperature ◽  
Mechanisms Of Action ◽  
The Body ◽  
Time Of Death ◽  
Rapid Loss ◽  
Higher Temperature ◽  
The Difference ◽  
Maintain Body Temperature

The acute toxicity of chlorpromazine in mice is 18 times higher in an environment of 4 °C than in a thermoneutral environment of 30 °C. Under similar conditions the acute toxicity of reserpine increases about 1200 times. These findings confirm the earlier suggestion that these drugs cause hypothermia by different mechanisms of action. Increased acute toxicity of these drugs was also noticed at a higher temperature (36 °C).At 4 °C, after chlorpromazine, death occurred earlier than after reserpine. Reserpine produced a transient increase in oxygen consumption (in rats) which helped maintain body temperature but resulted in a more rapid loss of heat from the body. This would explain the difference in time of death and might explain the difference in ultimate mortality between the animals treated with these two drugs.

“Lose Like a Man”: Gender and the Constraints of Self-Making in Weight Watchers Online

2017 ◽  
Vol 17 (1) ◽  
pp. 33-43
Author(s):  
Emily Contois
Keyword(s):  
Weight Loss ◽  
Technology Use ◽  
Hegemonic Masculinity ◽  
The Body ◽  
Online Programs ◽  
Men And Women ◽  
Male Clients ◽  
The Difference ◽  
Weight Watchers

Offering online programs that target men and women separately, Weight Watchers communicates, represents, and manipulates gender in its program marketing and materials. In this article, I demonstrate how Weight Watchers engages aspects of hegemonic masculinity as they endeavor to construct “masculine” versus “feminine” dieting through contrasting depictions of food, the body, and technology use. By analyzing the difference in the weight loss experiences that Weight Watchers Online promises, I argue that limited types of self are made available to women and men. Weight Watchers portrays female dieters on a difficult but actualizing and empowering journey toward a new and better self. Conversely, Weight Watchers depicts male clients losing weight easily, even effortlessly, but retaining a stable and immutable masculine selfhood throughout the process. This constraint upon self-making exposes how patriarchy subordinates even the men assumed to profit the most from its power, as the male weight loss promise withholds transformative potentials.

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