Evaluation of a Method for Estimating Food Consumption Rates of Fish

A method of estimating food consumption rates of fish in nature from laboratory growth data was evaluated using juvenile coho salmon (Oncorhynchus kisutch) in three similar experiments. One group of coho was held individually in aquariums where movement was restricted. Another group was maintained in an experimental stream where the coho displayed many of their typical behavior patterns. All fish were fed known rations and both groups had similar growth efficiencies over a wide range of rations. Coho feeding at intermediate rates had the highest gross efficiencies. Aggressive activity did not affect growth efficiency. Results suggested that laboratory food and growth data may provide reasonably accurate estimates of food consumption of coho salmon in nature.

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Breeding site selection by coho salmon (Oncorhynchus kisutch) in relation to large wood additions and factors that influence reproductive success

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/cjfas-2014-0020 ◽

2014 ◽

Vol 71 (10) ◽

pp. 1498-1507 ◽

Cited By ~ 3

Author(s):

Steven M. Clark ◽

Jason B. Dunham ◽

Jeffrey R. McEnroe ◽

Scott W. Lightcap

Keyword(s):

Site Selection ◽

Coho Salmon ◽

Oncorhynchus Kisutch ◽

Breeding Site ◽

Large Wood ◽

Fitness Components ◽

Breeding Sites ◽

Habitat Features ◽

Egg Incubation ◽

Wide Range

The fitness of female Pacific salmon (Oncorhynchus spp.) with respect to breeding behavior can be partitioned into at least four fitness components: survival to reproduction, competition for breeding sites, success of egg incubation, and suitability of the local environment near breeding sites for early rearing of juveniles. We evaluated the relative influences of habitat features linked to these fitness components with respect to selection of breeding sites by coho salmon (Oncorhynchus kisutch). We also evaluated associations between breeding site selection and additions of large wood, as the latter were introduced into the study system as a means of restoring habitat conditions to benefit coho salmon. We used a model selection approach to organize specific habitat features into groupings reflecting fitness components and influences of large wood. Results of this work suggest that female coho salmon likely select breeding sites based on a wide range of habitat features linked to all four hypothesized fitness components. More specifically, model parameter estimates indicated that breeding site selection was most strongly influenced by proximity to pool-tail crests and deeper water (mean and maximum depths). Linkages between large wood and breeding site selection were less clear. Overall, our findings suggest that breeding site selection by coho salmon is influenced by a suite of fitness components in addition to the egg incubation environment, which has been the emphasis of much work in the past.

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A laboratory-calibrated model of coho salmon growth with utility for ecological analyses

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/cjfas-2016-0506 ◽

2018 ◽

Vol 75 (5) ◽

pp. 682-690 ◽

Cited By ~ 1

Author(s):

Christopher V. Manhard ◽

Nicholas A. Som ◽

Russell W. Perry ◽

John M. Plumb

Keyword(s):

Food Availability ◽

Coho Salmon ◽

Meta Analysis ◽

Growth Patterns ◽

Growth Data ◽

Experimental Conditions ◽

Wide Range ◽

Klamath Basin ◽

Constructed Ponds ◽

Dependent Growth

We conducted a meta-analysis of laboratory- and hatchery-based growth data to estimate broadly applicable parameters of mass- and temperature-dependent growth of juvenile coho salmon (Oncorhynchus kisutch). Following studies of other salmonid species, we incorporated the Ratkowsky growth model into an allometric model and fit this model to growth observations from eight studies spanning ten different populations. To account for changes in growth patterns with food availability, we reparameterized the Ratkowsky model to scale several of its parameters relative to ration. The resulting model was robust across a wide range of ration allocations and experimental conditions, accounting for 99% of the variation in final body mass. We fit this model to growth data from coho salmon inhabiting tributaries and constructed ponds in the Klamath Basin by estimating habitat-specific indices of food availability. The model produced evidence that constructed ponds provided higher food availability than natural tributaries. Because of their simplicity (only mass and temperature are required as inputs) and robustness, ration-varying Ratkowsky models have utility as an ecological tool for capturing growth in freshwater fish populations.

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Error in Estimation of Feeding Rates from Changes in Mean Body Mass

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f88-176 ◽

1988 ◽

Vol 45 (8) ◽

pp. 1494-1498 ◽

Cited By ~ 7

Author(s):

P. A. Cochran ◽

K. J. Knutsen

Keyword(s):

Food Intake ◽

Food Consumption ◽

Body Mass ◽

Micropterus Salmoides ◽

Feeding Rates ◽

Growth Data ◽

Typical Application ◽

Consumption Rates ◽

Actual Field ◽

Change In Mean

Because of nonlinear relationships between body mass and many parameters in energetics models, rates of food intake calculated from change in mean body mass (a typical application of energetics models) do not necessarily equal true mean rates of food intake calculated from individual changes in body mass. Using both hypothetical data and actual field data for largemouth bass (Micropterus salmoides) marked with individually numbered tags, we show that discrepancies increase with variability in body mass but are negligible (< 3.5%) in all cases examined. Biased estimates of change in mean body mass, such as might result from size-selective mortality or sampling gear, can lead to substantial errors in energetics model estimates of mean food consumption rates. Use of growth data for individually marked fish in conjunction with an energetics model permits calculation of confidence intervals, statistical comparison of food consumption rates, and examination of relationships between foraging success and individual body mass.

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Selection for Adult Size in Female Coho Salmon (Oncorhynchus kisutch)

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f86-240 ◽

1986 ◽

Vol 43 (10) ◽

pp. 1946-1959 ◽

Cited By ~ 60

Author(s):

L B. Holtby ◽

M. C. Healey

Keyword(s):

Coho Salmon ◽

Pacific Salmon ◽

Oncorhynchus Kisutch ◽

Selective Advantage ◽

Evolutionary Stable Strategy ◽

Relative Fitness ◽

Female Size ◽

Adult Size ◽

Stable Strategy ◽

Wide Range

Several recent studies have presented evidence that large size confers a selective advantage to female Pacific salmon. Nevertheless, a wide range of female sizes is normally present in any spawning population. Two possible explanations exist for the observed range in female size. First, average female size might be determined by an optimizing process with variation around the optimum size due to individual differences in success at obtaining food. Second, various sizes of females might coexist as a mixed evolutionary stable strategy. Under the first explanation, females of sizes other than the optimum would display lower fitness whereas, under the second explanation, females of all sizes would be equally fit. We investigated factors affecting survival of eggs, fry, and smolts of coho salmon (Oncorhynchus kisutch) in Carnation Creek on Vancouver Island with a view to determining the relative fitness of different sized females. Egg-to-fry mortality was best explained by a model that included only the effects of stream bed scour and gravel quality. Including an effect of female size, expressed through depth of egg burying, worsened the model's predictive capability. We could find no evidence that the eggs of large females consistently survived better during incubation than those of small females. In fact, we observed three instances in which it appeared that the eggs of small females survived better. In Carnation Creek, large 1- and 2-yr-old smolts did not consistently survive better in the marine environment than small smolts. Thus, we were unable to demonstrate that the reproductive success of large females was consistently higher than that of small females, contrary to the hypothesis that female size is the result of an optimizing process. In Carnation Creek the observed range of female sizes probably represents an evolutionary stable strategy in which all sizes have equal fitness. We propose a model that predicts female size and variance in size based on the conflicting selective effects of gravel quality, scour, and competition for nest sites.

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Influence of orally administered L-thyroxine or 3,5,3′-triiodo-L-thyronine on growth, food consumption, and food conversion of underyearling coho salmon (Oncorhynchus kisutch)

Canadian Journal of Zoology ◽

10.1139/z79-261 ◽

1979 ◽

Vol 57 (10) ◽

pp. 1974-1979 ◽

Cited By ~ 69

Author(s):

David A. Higgs ◽

U. H. M. Fagerlund ◽

J. R. McBride ◽

J. G. Eales

Keyword(s):

Food Consumption ◽

Coho Salmon ◽

Condition Factor ◽

Oncorhynchus Kisutch ◽

Food Conversion ◽

Thyroid Follicle ◽

Natural Photoperiod

Between August and November, groups of underyearling coho salmon, held at 10 °C and on a natural photoperiod, were fed twice daily to satiation with Oregon moist pellets supplemented with 0, 20, 100. or 500 ppm of L-thyroxine (T4) or 3,5,3′-triiodo-L-thyronine (T3).The T3 significantly increased weight (20 and 100 ppm) and length (all doses), depressed condition factor (100 and 500 ppm), stimulated food consumption (20 ppm), improved food conversion (all doses), decreased thyroid follicle epithelial height (500 ppm), and influenced pituitary basophil and somatotrop number, size, and granulation.The T4 influenced neither growth nor food conversion, but did increase food consumption (20 ppm) and condition factor (500 ppm). and decreased thyroid follicle epithelial height (500 ppm).No breakdown of either added T4 or T3 was observed during prolonged food storage.It is concluded that T3 unlike T4, can be administered in the diet of coho held at 10 °C to enhance growth and improve food conversion.

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Cereal Consumption, Production, and Prices in West Pakistan (Notes & Comments)

The Pakistan Development Review ◽

10.30541/v8i2pp.288-306 ◽

1968 ◽

Vol 8 (2) ◽

pp. 288-306 ◽

Cited By ~ 1

Author(s):

G. C. Hufbauer

Keyword(s):

Food Consumption ◽

Ad Hoc ◽

Dry Weight ◽

Small Sample ◽

Tax Rates ◽

Active Population ◽

Early Settlement ◽

Consumption Rates ◽

Late Nineteenth ◽

Better Than

In the late nineteenth and early twentieth centuries, several Punjab Settlement Officers attempted to estimate food consumption rates. These estimates, based on direct observation and ad hoc guesses, were made partly out of academic curiosity, but more urgently, as an aid in establishing the land revenue (i.e., tax) rates. The pre-1926 estimates are summarized in Table I, expressed in pounds of wheat and other foodgrain consumption per person per year1. Broadly speaking, the later, more systemtic observers (e.g., Sir Ganga Ram and C. B. Barry), found lower consumption levels than the earlier observers. It was generally accepted that the rural populace ate better than urban dwellers. Despite the ingenuity of the early Settlement Officers, their compiled estimates suffer from all the difficulties of haphazard small sample observation. Given the revenue purpose of the estimates, they may be biased towards the able-bodied, economically active, population. Further, the very early estimates may have confused dry weight with cooked weight, including water.

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