Energy allocation in larval and juvenile Coregonus lavaretus: validation of a bioenergetics model (original) (raw)
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Journal of Fish Biology, 1997
The two most commonly used methods for estimating the food consumption of fish are based on either the evacuation rate of food or the energy budget of an individual fish. In this study, both of those methods were used to estimate the food consumption of fish under experimental conditions. Bioenergetics models of vendace Coregonus albula, smelt Osmerus eperlanus, roach Rutilus rutilus and perch Perca fluviatilis were reconstructed based on experimental data and published values. The precision of the bioenergetics estimates for food consumption was evaluated under experimental conditions. The modelling efficiency (EF) of the bioenergetics model was 0.90, 0.97 and 0.93 for coregonids, roach and perch, respectively, which indicated good agreement between observed and predicted values. Under our experimental conditions, the bioenergetics model estimated food consumption better than the evacuation rate model.
DOI: 10.1577/T04-215.1 Evaluation of a Lake Whitefish Bioenergetics Model
2014
Abstract.—We evaluated the Wisconsin bioenergetics model for lake whitefish Coregonus clu-peaformis in the laboratory and in the field. For the laboratory evaluation, lake whitefish were fed rainbow smelt Osmerus mordax in four laboratory tanks during a 133-d experiment. Based on a comparison of bioenergetics model predictions of lake whitefish food consumption and growth with observed consumption and growth, we concluded that the bioenergetics model furnished significantly biased estimates of both food consumption and growth. On average, the model over-estimated consumption by 61 % and underestimated growth by 16%. The source of the bias was probably an overestimation of the respiration rate. We therefore adjusted the respiration component of the bioenergetics model to obtain a good fit of the model to the observed consumption and growth in our laboratory tanks. Based on the adjusted model, predictions of food consumption over the 133-d period fell within 5 % of observed consumptio...
Preliminary Evaluation of a Lake Whitefish (Coregonus clupeaformis) Bioenergetics Model
2000
We conducted a preliminary evaluation of a lake whitefish (Coregonus clupeaformis) bioenergetics model by applying the model to size-at-age data for lake whitefish from northern Lake Michigan. We then compared estimates of gross growth efficiency (GGE) from our bioenergetics model with previously published estimates of GGE for bloater (C. hoyi) in Lake Michigan and for lake whitefish in Quebec. According to our model, the GGE of Lake Michigan lake whitefish decreased from 0.075 to 0.02 as age increased from 2 to 5 years. In contrast, the GGE of lake whitefish in Quebec inland waters decreased from 0.12 to 0.05 for the same ages. When our swimming-speed submodel was replaced with a submodel that had been used for lake trout (Salvelinus namaycush) in Lake Michigan and an observed predator energy density for Lake Michigan lake whitefish was employed, our model predicted that the GGE of Lake Michigan lake whitefish decreased from 0.12 to 0.04 as age increased from 2 to 5 years.
Additive budgeting of metabolic costs in larval coregonids
Commonly used bioenergetics models of fish assume that the energy budget is additive, that is, each component of the budget has its own allocation and at least the basal level of this specific capacity cannot be used for other purposes. However, it has been proposed that rapidly growing fish larvae with a narrow metabolic scope may have to reduce the energy allocated to activity or maintenance in order to maintain high growth rates. This has been called previously compensatory budgeting. In the present study, we addressed this important issue by conducting swimming respirometer experiments and reanalysing previous feeding respirometer data using larval whitefish. In the swimming respirometer, the total metabolic rate of unfed larvae was lower than the total rate of fed larvae, in which the total rate increased with increasing ration. The swimming respirometer experiments suggested that the costs of digestion and activity have their own basal requirements and are at least to some extent independent. The reanalysis of the feeding respirometer data showed that up to a specific growth rate of about 16% day -1 no suppression of maintenance functions is needed to achieve high growth rates. These results together suggest that the energy budget of larval whitefish is indeed additive, and that this assumption is therefore justified as a theoretical base in modelling larval coregonid energetics.
Evaluation of a Lake Whitefish Bioenergetics Model
Transactions of the American Fisheries Society, 2006
We evaluated the Wisconsin bioenergetics model for lake whitefish Coregonus clupeaformis in the laboratory and in the field. For the laboratory evaluation, lake whitefish were fed rainbow smelt Osmerus mordax in four laboratory tanks during a 133-d experiment. Based on a comparison of bioenergetics model predictions of lake whitefish food consumption and growth with observed consumption and growth, we concluded that the bioenergetics model furnished significantly biased estimates of both food consumption and growth. On average, the model overestimated consumption by 61% and underestimated growth by 16%. The source of the bias was probably an overestimation of the respiration rate. We therefore adjusted the respiration component of the bioenergetics model to obtain a good fit of the model to the observed consumption and growth in our laboratory tanks. Based on the adjusted model, predictions of food consumption over the 133-d period fell within 5% of observed consumption in three of the four tanks and within 9% of observed consumption in the remaining tank. We used polychlorinated biphenyls (PCBs) as a tracer to evaluate model performance in the field. Based on our laboratory experiment, the efficiency with which lake whitefish retained PCBs from their food (␥) was estimated at 0.45. We
Transactions of the American Fisheries Society, 2008
Fish proximate composition and energy density can influence growth, survival, and reproduction, so it is important to develop models to understand the patterns and predict dynamic changes. This paper presents three such models. Model 1 describes the general pattern of changes in lipid, protein, ash, and energy density that occur with changes in water content. The key assumption this model is that there is a fixed amount of water associated with each gram of protein and a much smaller fixed amount of water associated with each gram of lipid. In combination with a mass balance constraint, this explains the commonly observed linear relationship between the fraction lipid and the fraction water. Because energy density varies in direct proportion to the fractions lipid and protein, the linear relationship between body composition and fraction water makes energy density also a linear function of the fraction water. The model is fitted to data for lake trout Salvelinus namaycush and coho salmon Oncorhynchus kisutch for a limited range in wet weight. Model 2 describes the pattern of proximate composition and energy density that occurs with variation in body size. A strong pattern was found between the mass of water and the mass of protein, suggesting strict control of body water. The model is fitted to data for common carp Cyprinus carpio and bluegill Lepomis macrochirus. This analysis shows that the relationship between body composition, energy density, and fraction water is expected to vary with body size because both the water : protein ratio and the fraction ash change with body size. Model 3 demonstrates how this approach can be used to predict changes in fish body composition and energy density during starvation, as might be done with a bioenergetics model. This model is fitted to data from a starvation experiment involving largemouth bass Micropterus salmoides. A model for fish proximate composition and energy density would improve understanding of observed patterns in fish body composition data and enhance bioenergetics models of fish growth. A model for proximate composition could help explain two common patterns related to percent lipid and energy density, which are linearly related to percent water (
Modelling growth and body composition in fish nutrition: where have we been and where are we going
Aquaculture Research, 2010
Mathematical models in fish nutrition have proven indispensable in estimating growth and feed requirements. Nowadays, reducing the environmental footprint and improving product quality of fish culture operations are of increasing interest. This review starts by examining simple models applied to describe/predict fish growth profiles and progresses towards more comprehensive concepts based on bioenergetics and nutrient metabolism. Simple growth models often lack biological interpretation and overlook fundamental properties of fish (e.g. ectothermy, indeterminate growth). In addition, these models disregard possible variations in growth trajectory across life stages. Bioenergetic models have served to predict not only fish growth but also feed requirements and waste outputs from fish culture operations. However, bioenergetics is a concept based on energy-yielding equivalence of chemicals and has significant limitations. Nutrient-based models have been introduced into the fish nutrition literature over the last two decades and stand as a more biologically sound alternative to bioenergetic models. More mechanistic models are required to expand current understanding about growth targets and nutrient utilization for biomass gain. Finally, existing models need to be adapted further to address effectively concerns regarding sustainability, product quality and body traits.
Journal of Fish Biology, 1988
The feeding activity of an individual fish larva is described by an equation which includes parameters for the area successfully searched, probability of food capture multiplied by the cross-sectional perceptive visual field, larval swimming speed and the time required to consume a unit of food energy. The proportion of ingested food energy used for metabolism increases exponentially with increasing swimming speed. The model predicts that food consumption rate increases asymptotically whereas metabolic rate increases exponentially. This results in a predicted growth rate curve that reaches a maximum at a certain swimming speed and decreases at both higher and lower speeds.The model can be used to predict the influence of type of prey, prey density, water temperature etc. on larval growth. An expression describing how many hours per day fish larvae must forage in order to grow at a certain daily body weight gain allows the limits of environmental conditions for positive, zero and negative growth rate to be set.Results of simulations demonstrated that the optimum swimming speed for maximum growth of coregonid larvae increased with an increase in food density, decrease in water temperature or decrease of prey vulnerability. At optimum ‘theoretical’ swimming speed an increase in water temperature from 5 to 17° C required the food density to be increased from 20 to 80 copepods l−1 in order to maintain a daily growth increment of 2%. The minimum Artemia density required for maintenance metabolism increased from 10 to 30 items 11 over the same temperature increase from 5 to 17° C, and food densities required for 8% growth rates were 26 and 56 Artemia nauplii l−1 at 5 and 17° C, respectively.Contrary to previous findings, results of the present study suggest that metabolic rates of actively feeding fish larvae may be from 5 to 50 times the standard metabolic rate: earlier studies suggested that a factor of 2–3 may be generally applicable.
A bioenergetics model for juvenile flounder Platichthys flesus
Journal of Applied Ichthyology, 2006
Despite the numerous physiological studies on flatfish and their economic and ecologic importance, only a few attempts have been made to construct a bioenergetics model for these species. Here we present the first bioenergetics model for European flounder (Platichthys flesus), using experimentally derived parameter values. We tested model performance using literature derived field-based estimates of food consumption and growth rates of an estuarine flounder population in the Ythan estuary, Scotland. The model was applied to four age-classes of flounder (age 0–3). Sensitivity of model predictions to parameter perturbation was estimated using error analysis. The fit between observed and predicted series was evaluated using three statistical methods: partitioning mean squared error, a reliability index (RI) and an index of modelling efficiency (MEF). Overall, model predictions closely tracked the observed changes of consumption and growth. The results of the different validation techniques show a high goodness-of-fit between observed and simulated values. The model clearly demonstrates the importance of temperature in determining growth of flounder in the estuary. A sex-specific estimation of the energetic costs of spawning in adult flounder and a more accurate description of the thermal history of the fish may further reduce the error in the model predictions.
Journal of Fish Biology, 2003
Laboratory growth and food consumption data for two size classes of age 2 year yellow perch Perca flavescens, each fed on two distinct feeding schedules at 21 C, were used to evaluate the abilities of the Wisconsin (WI) and Karas^Thoresson (KT) bioenergetics models to predict fish growth and cumulative consumption. Neither model exhibited consistently better performance for predicting fish body masses across all four fish size and feeding regime combinations. Results indicated deficiencies in estimates of resting routine metabolism by both models. Both the WI and KT models exhibited errors for predicting growth rates, which were strongly correlated with food consumption rate. Consumption-dependent prediction errors may be common in bioenergetics models and are probably the result of deficiencies in parameter values or assumptions within the models for calculating energy costs of specific dynamic action, feeding activity metabolism or egestion and excretion. Inter-model differences in growth and consumption predictions were primarily the result of differences in egestion and excretion costs calculated by the two models. The results highlighted the potential importance of parameters describing egestion and excretion costs to the accuracy of bioenergetics model predictions, even though bioenergetics models are generally regarded as being insensitive to these parameters. The findings strongly emphasize the utility and necessity of performing laboratory evaluations of all bioenergetics models for assurance of model accuracy and for facilitation of model refinement.