Comparison of activity rates of 1+ yellow perch (Perca flavescens) from populations of contrasting growth rates using underwater video observations

1999 ◽  
Vol 56 (6) ◽  
pp. 1122-1132 ◽  
Author(s):  
N Aubin-Horth ◽  
J Gingras ◽  
D Boisclair
Keyword(s):  
Growth Rates ◽  
Yellow Perch ◽  
Perca Flavescens ◽  
Daily Consumption ◽  
Lower Growth ◽  
Average Growth ◽  
Video Observations ◽  
Consumption Rates ◽  
The Difference ◽  
Two Populations

We compared the stereocinematographic (SCG) method to estimate activity rates of yellow perch (Perca flavescens) with the more traditional bioenergetic approach. We also compared activity rates of perch from two populations with contrasting growth rates to test the hypothesis that fish with lower growth rates are characterized by higher activity rates. We attempted to corroborate the SCG method by comparing values of energetic costs obtained with observations of fish movements with estimates obtained using the difference between field-derived consumption and growth rates (bioenergetic method). Independent estimates of consumption and activity rates were obtained for Lakes Hertel (average growth = 172 J·day-1) and Memphremagog (average growth = 595 J·day-1). Daily consumption rates averaged 720 J·day-1 in Lake Hertel and 1457 J·day-1 in Lake Memphremagog. SCG and bioenergetic methods provided similar activity estimates for Lake Hertel (<2.5% difference) and diverged by 0.4-82% for Lake Memphremagog depending on initial values of fish weight or consumption inputted in the bioenergetic equation. Regardless of the method employed, activity rates of fish from Lake Hertel were proportionally higher (24% of consumption rates) than those from Lake Memphremagog (on average 13% of consumption rates). Our work supported the suggestion that populations with slower growth rates may be associated with proportionally higher activity rates.

Effects of turbidity on prey consumption and growth in brook trout and implications for bioenergetics modeling

2001 ◽  
Vol 58 (2) ◽  
pp. 386-393 ◽  
Author(s):  
John A Sweka ◽  
Kyle J Hartman
Keyword(s):  
Growth Rates ◽  
Brook Trout ◽  
Specific Growth ◽  
Abiotic Factors ◽  
Foraging Strategies ◽  
Turbid Water ◽  
Daily Consumption ◽  
Consumption Rates ◽  
The Difference ◽  
Specific Growth Rates

Brook trout (Salvelinus fontinalis) were held in an artificial stream to observe the influence of turbidity on mean daily consumption and specific growth rates. Treatment turbidity levels ranged from clear (<3.0 nephelometric turbidity units (NTU)) to very turbid water (> 40 NTU). Observed mean daily specific consumption rates were standardized to the mean weight of all brook trout tested. Turbidity had no significant effect on mean daily consumption, but specific growth rates decreased significantly as turbidity increased. Brook trout in turbid water became more active and switched foraging strategies from drift feeding to active searching. This switch was energetically costly and resulted in lower specific growth rates in turbid water as compared with clear water. Bioenergetics simulations were run to compare observed growth with that predicted by the model. Observed growth values fell below those predicted by the model and the difference increased as turbidity increased. Abiotic factors, such as turbidity, which bring about changes in the activity rates of fish, can have implications for the accuracy of predicted growth by bioenergetics models.

Interactions between White Perch (Morone amerićana) and Yellow Perch (Perca flavescens) in Lake Erie as Determined from Feeding and Growth

1990 ◽  
Vol 47 (9) ◽  
pp. 1779-1787 ◽  
Author(s):  
Donna L. Parrish ◽  
F. Joseph Margraf
Keyword(s):  
Food Consumption ◽  
Yellow Perch ◽  
White Perch ◽  
Perca Flavescens ◽  
Diet Overlap ◽  
Central Basin ◽  
Morone Americana ◽  
Western Basin ◽  
Consumption Rates ◽  
Growth Differences

Since the mid-1970's, white perch Morone americana have expanded rapidly, resulting in possible major interactions with the native yellow perch Perca flavescens. We compared the food consumption rates, diet overlap, and growth of white perch and yellow perch from field data collected during 1983–85 and 1987. Food consumption rates were as much as 27% greater in white perch than in yellow perch, and were higher for both species in the central basin than in the western basin. Seasonal diet composition was most alike in summer and less so in spring and fall, when yellow perch ate more benthos or fish than did white perch. Of 48 Schoener index comparisons of diet overlap during a 3-yr period, 52% were significant (> 0.6). Although yellow perch grew faster in the central basin, reflecting the greater consumption rates, white perch did not show the similar large interbasin growth differences.

Natural Sources and Requirements of Phosphorus for Fishes

1980 ◽  
Vol 37 (4) ◽  
pp. 679-686 ◽  
Author(s):  
Brian S. Nakashima ◽  
William C. Leggett
Keyword(s):  
Yellow Perch ◽  
Perca Flavescens ◽  
Absorption Efficiency ◽  
Available Phosphorus ◽  
Temperature Dependent ◽  
Daily Consumption ◽  
Natural Prey ◽  
Dietary Phosphorus ◽  
Daily Food ◽  
Phosphorus Levels

The hypothesis that daily consumption of natural prey provides a source of phosphorus sufficient to meet growth and metabolic requirements of fishes is examined. Fish may be capable of utilizing available phosphorus directly from the water; however, this source is negligible in comparison to dietary intake. Experiments were designed to test the effect of different dietary phosphorus levels, chosen to approximate those of natural prey items, on growth of juvenile perch at temperatures encountered during the growing season. Rations were based upon estimates of daily food consumption for perch in Lake Memphremagog. Growth was significantly temperature-dependent and independent of dietary phosphorus levels. Phosphorus:ash ratios of whole fish were not significantly different among diet treatments or between the initiation and termination of the growth experiment. Excretion of phosphorus was positively related to phosphorus intake.Key words: absorption efficiency, daily ration, growth, Lake Memphremagog, nutrition, Perca flavescens, phosphorus budget, yellow perch

scholarly journals Assessing the lockdown effect from excess mortalities

2021 ◽  
Author(s):  
Alexej Weber
Keyword(s):  
Growth Rate ◽  
South Korea ◽  
Growth Rates ◽  
Excess Mortality ◽  
Reproduction Number ◽  
Average Growth Rate ◽  
Average Growth ◽  
Reproduction Numbers ◽  
The Difference ◽  
Pharmaceutical Interventions

AbstractBackground and AimsThe reported case numbers of COVID-19 are often used to estimate the reproduction number or the growth rate. We use the excess mortality instead, showing the difference between most restrictive non-pharmaceutical interventions (mrNPIs) and less restrictive NPIs (lrNPIs) with respect to the growth rate and death counts.MethodsWe estimate the COVID-19 growth rate for Sweden, South Korea, Italy and Germany from the excess mortality. We use the average growth rate obtained for Sweden and South Korea, two countries with lrNPIs, to estimate additional death numbers in Germany and Italy (two countries with mrNPIs) in a hypothetic lrNPIs scenario.ResultsThe growth rate estimated from excess mortality decreased faster for Germany and Italy than for Sweden and South Korea, suggesting that the mrNPIs have a non-negligible effect. This is not visible when the growth rate is calculated using the reported case numbers of COVID-19. This results in approximately 4 500 and 12 000 more death numbers for Germany and Italy, respectively.ConclusionThe reproduction numbers or growth rates obtained from reported COVID-19 cases are most likely biased. Expanding testing capacity led to an overestimation of the growth rate across all countries analyzed, masking the true decrease already visible in the excess mortality. Using our method, a more realistic estimate of the growth rate is obtained. Conclusions made for the reproduction number derived from the reported case numbers like the insignificance of most restrictive non-pharmaceutical interventions (lockdowns) might be wrong and have to be reevaluated using the growth rates obtained with our method.

The Importance of Activity in Bioenergetics Models Applied to Actively Foraging Fishes

1989 ◽  
Vol 46 (11) ◽  
pp. 1859-1867 ◽  
Author(s):  
D. Boisclair ◽  
W. C. Leggett
Keyword(s):  
Food Consumption ◽  
Yellow Perch ◽  
Perca Flavescens ◽  
Population Differences ◽  
Population Variance ◽  
Population Activity ◽  
Consumption Rates ◽  
Activity Costs ◽  
Food Consumption Estimates ◽  
Bioenergetics Models

We used the Kitchell et al. (J. Fish. Res. Board Can. 34: 1922–1935) bioenergetics model and field derived estimates of growth and consumption rates to estimate the quantity of energy allocated to activity by 28 combinations of yellow perch (Perca flavescens) age class and population. Activity costs among populations ranged from 0 to 40% of the perch bioenergetics budget. We further evaluated the influence of activity rates on the food consumption estimates predicted by the Kitchell et al. model and the model proposed by Kerr (Can. J. Fish. Aquat. Sci. 39: 371–379). As suggested by Kerr, activity costs increased as food consumption increased. However, we found no significant relationship between predicted and observed food consumption estimates for either model. The magnitude of, and the among-population variance in, the quantity of energy allocated to activity is consistent with our hypothesis that this component of the bioenergetics budget of fishes has the potential to contribute meaningfully to the explanation of inter-population differences in perch growth and, by extension, to the variance in growth of other actively foraging fish species.

scholarly journals Food Consumption and Growth Rates of Juvenile Black Carp Fed Natural and Prepared Feeds

2014 ◽  
Vol 5 (1) ◽  
pp. 35-45 ◽  
Author(s):  
Nathaniel C. Hodgins ◽  
Harold L. Schramm ◽  
Patrick D. Gerard
Keyword(s):  
Food Consumption ◽  
Growth Rates ◽  
Specific Growth ◽  
Daily Consumption ◽  
Black Carp ◽  
Consumption Rates ◽  
Wet Weight ◽  
Feeding Trials ◽  
Specific Growth Rates ◽  
Weight Number

Abstract The introduced mollusciphagic black carp Mylopharyngodon piceus poses a significant threat to native mollusks in temperate waters throughout the northern hemisphere, but consumption rates necessary to estimate the magnitude of impact on mollusks have not been established. We measured food consumption and growth rates for small (77–245 g) and large (466–1,071 g) triploid black carp held individually under laboratory conditions at 20, 25, and 30°C. Daily consumption rates (g food · g wet weight fish−1·d−1·100) of black carp that received prepared feed increased with temperature (small black carp 1.39–1.71; large black carp 1.28–2.10), but temperature-related increases in specific growth rate (100[ln(final weight) - ln(initial weight)]/number of days) only occurred for the large black carp (small black carp −0.02 to 0.19; large black carp 0.16–0.65). Neither daily consumption rates (5.90–6.28) nor specific growth rates (0.05–0.24) differed among temperatures for small black carp fed live snails. The results of these laboratory feeding trials indicate food consumption rates can vary from 289.9 to 349.5 J·g−1·d−1 for 150 g black carp receiving prepared feed, from 268.8 to 441.0 J·g−1·d−1for 800 g black carp receiving prepared feed, and from 84.8 to 90.2 J·g−1·d−1 for 150 g black carp that feed on snails. Applying estimated daily consumption rates to estimated biomass of native mollusks indicates that a relatively low biomass of black carp could eliminate native snails and substantially reduce recruitment of mussels in time periods as short as 180 d.

Variability in First-Year Growth of Yellow Perch (Perca flavescens): Predictions from a Simple Model, Observations, and an Experiment

1994 ◽  
Vol 51 (11) ◽  
pp. 2501-2512 ◽  
Author(s):  
John R. Post ◽  
Donald J. McQueen
Keyword(s):  
Simple Model ◽  
Growth Rates ◽  
Yellow Perch ◽  
Explanatory Power ◽  
Perca Flavescens ◽  
Negative Relationship ◽  
Zooplankton Community ◽  
Prey Abundance ◽  
First Year ◽  
Growth Variability

First-year growth of yellow perch, Perca flavescens, varies by greater than an order of magnitude among populations and among cohorts within populations. The variability in growth rates of natural and enclosure-reared young-of-the-year yellow perch could be explained by the availability of benthic and/or plank-tonic prey (R2 = 0.093–0.098). Mean annual water temperature and cumulative degree-days did not add to the explanatory power of the relationships. The faster growing natural cohorts included more benthos in their diet; however, benthos is not necessary to sustain the highest growth rates because the fastest growth rates were observed in enclosure cohorts that lacked benthic invertebrates. Cohorts in lakes and enclosures that had a high proportion of Daphnia in the zooplankton community also supported higher first-year growth rates. The results of the enclosure experiment suggest that the dominant mechanism creating growth variability is density-dependent intra-age-class competition. Our empirical results, when coupled with a simple model, suggest that the assumption of a negative relationship between energetic costs of foraging and prey abundance, on a daily time scale, is the most appropriate because it acts to amplify growth variability across ranges of prey abundance.

scholarly journals The Development of Sunspot Groups

1993 ◽  
Vol 141 ◽  
pp. 492-494
Author(s):  
Robert F. Howard
Keyword(s):  
Tilt Angle ◽  
Growth Rates ◽  
Large Scale ◽  
Decay Rates ◽  
Average Growth ◽  
Average Value ◽  
Percentage Area ◽  
Flux Loops ◽  
The Difference ◽  
Sunspot Groups

AbstractIt is shown that the growth and decay rates of sunspot groups are both a function of the axial tilt angles of the groups. Both of these rates reach a maximum near the average tilt angle, which is around +5°, not 0°. (A positive tilt angle represents the situation where the leading spots are equatorward of the following spots). The fact that this peak angle is close to the average tilt and not 0° suggests that this may be the orientation of the subsurface toroidal flux tube(s) from which the sunspot groups form. In general, spot groups with positive tilt angles show faster average percentage growth rates for greater positive tilt angles. For negative tilt angles (following spots equatorward of leading spots) the situation is quite different. Within certain well-defined ranges of tilt angles the average group percentage area growth rates are quite high and the dispersion in this quantity is large. In other well-defined tilt angle ranges the percentage growth rates are uniformly (relatively) small. The difference between these average growth rates is more than a factor two. The reality of this result can be demonstrated by selecting for analysis various subsets of the data. It may be hypothesized that in general the dispersion measured in group tilt angles results from the random action of large-scale convection on the rising magnetic flux loops. Both growth and decay are facilitated in the case of flux loops that have a minimum twist. The percentage growth and decay rates are affected by the fact that groups with tilt angles near the average value tend to be larger than groups with different tilt angles. The ‘quantized’ behavior of the percentage growth rates for negative tilt angles is difficult to fit into any rough model of flux emergence. The more or less ‘quantized’ nature of the growth-tilt angle relationship for negative tilt angles is quite puzzling and may reflect some characteristic of the subsurface flux orientation or development which is at present unknown.

Changes in Yellow Perch (Perca flavescens) Populations of Lake Michigan, 1954–75

1977 ◽  
Vol 34 (10) ◽  
pp. 1821-1829 ◽  
Author(s):  
LaRue Wells
Keyword(s):  
Population Dynamics ◽  
Growth Rates ◽  
Yellow Perch ◽  
Lake Michigan ◽  
Perca Flavescens ◽  
Commercial Production ◽  
Alosa Pseudoharengus ◽  
Exploitation Competition ◽  
Sport Fishery ◽  
High Production

In the early and mid-1960s the abundance of yellow perch (Perca flavescens) in Lake Michigan declined abruptly. The decline began in the northern part of the lake and spread progressively southward. Circumstantial evidence suggests that the nonnative alewife (Alosa pseudoharengus), by interfering with perch reproduction, was the primary cause of the decline. The alewife was first reported in northeastern Lake Michigan in 1949, and had become extremely abundant throughout the lake before an enormous die-off in 1967 reduced its numbers by an estimated 70%. An intensive fishery hastened the decline of perch. In most areas the decline was immediately preceded by a period of conspicuously high commercial production. This high production appears to have been related in part to increased growth rates of perch resulting from much lower density of younger fish. A sport fishery for perch in shallow water collapsed a few years before the species declined in abundance. The most logical explanation is that heavy concentrations of alewives physically displaced the perch from nearshore areas. Although perch populations increased in some areas in the 1970s, a full recovery is unlikely unless alewife numbers are further reduced. Key words: Percidae, Lake Michigan, Perca, population dynamics, exploitation, competition

Metabolic Allometry of Larval and Juvenile Yellow Perch (Perca flavescens): In Situ Estimates and Bioenergetic Models

1990 ◽  
Vol 47 (3) ◽  
pp. 554-560 ◽  
Author(s):  
John R. Post
Keyword(s):  
Food Consumption ◽  
Yellow Perch ◽  
Prey Availability ◽  
Juvenile Fish ◽  
Perca Flavescens ◽  
Growth Dynamics ◽  
Model Simulations ◽  
Consumption Rates ◽  
Young Of The Year

Measurements of in situ food consumption and growth rates of young-of-the-year (YOY) yellow perch, Perca flavescens, indicated that extrapolations of the metabolic allometry of adult perch to larval and juvenile perch were inappropriate. YOY active metabolism had the same weight dependent slope as adults but was 4.4 times adult standard respiration. Adult active respiration is typically 1–2 times standard. YOY consumption rates were also higher than predicted from adult allometry. Model simulations demonstrate that consumption and growth dynamics of larval and juvenile fish are more sensitive to variation in temperature and prey availability than are adults.

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