Estimating the Energy Budgets of Actively Predatory Fishes

1982 ◽  
Vol 39 (3) ◽  
pp. 371-379 ◽  
Author(s):  
S. R. Kerr
Keyword(s):  
Gadus Morhua ◽  
Natural Populations ◽  
Estimation Procedure ◽  
Energy Budgets ◽  
Energy Accumulation ◽  
Surplus Energy ◽  
Bioenergetic Analysis ◽  
Growth Metabolism ◽  
Predatory Fishes ◽  
Primary Advantage

Where estimates of surplus energy accumulation are available, bioenergetic analysis of fish in nature requires estimates of the associated ration or metabolic levels. The estimation procedure described here is based upon direct coupling of ration intake with the activity metabolism subcomponent of total metabolism. Its primary advantage over other estimation procedures is in its simple, generalized handling of activity metabolism. Application of the method is illustrated for natural populations of cod, Gadus morhua, and haddock, Melanogrammus aeglefinus.Key words: bioenergetics, growth, metabolism, rations, cod, haddock

Pelagic fishes and the cod recruitment dilemma in the Northwest Atlantic

2000 ◽  
Vol 57 (7) ◽  
pp. 1321-1325 ◽  
Author(s):  
D P Swain ◽  
A F Sinclair
Keyword(s):  
Gadus Morhua ◽  
Atlantic Cod ◽  
Negative Relationship ◽  
Early Life History ◽  
Recruitment Rate ◽  
Clupea Harengus ◽  
Northwest Atlantic ◽  
Life History Stages ◽  
Pelagic Fishes ◽  
Predatory Fishes

Like most other stocks of Atlantic cod (Gadus morhua) in the Northwest Atlantic, cod in the southern Gulf of St. Lawrence declined to low abundance in the early 1990s. Recovery has been slow in contrast with the rapid recovery from similar levels of abundance in the mid-1970s. This difference reflects remarkably high prerecruit survival of cod in the earlier period of low abundance rather than unusually poor survival in the 1990s. The period of high prerecruit survival of cod coincided with the collapse of herring (Clupea harengus) and mackerel (Scomber scombrus) stocks resulting from overfishing. These pelagic fishes are potential predators or competitors of the early life history stages of cod. We report a strong negative relationship between the biomass of these pelagic fishes and recruitment rate of southern Gulf cod. This is consistent with the recent suggestion that the success of large predatory fishes may depend on "cultivation" effects in which the adults crop down forage fishes that are predators or competitors of their young. Our results also point to the possibility of a triangular food web involving cod, seals, and pelagic fishes, making it difficult to predict the effect of a proposed cull of seals on the recovery of cod.

Maternal age, fecundity, egg quality, and recruitment: linking stock structure to recruitment using an age-structured Ricker model

2012 ◽  
Vol 69 (10) ◽  
pp. 1631-1641 ◽  
Author(s):  
Andrew O. Shelton ◽  
Stephan B. Munch ◽  
David Keith ◽  
Marc Mangel
Keyword(s):  
Age Structure ◽  
Maternal Age ◽  
Gadus Morhua ◽  
Egg Quality ◽  
Atlantic Cod ◽  
Natural Populations ◽  
Ricker Model ◽  
Icelandic Population ◽  
Spawning Stock ◽  
Age Structured

Understanding the process of recruitment is fundamental to fisheries biology and management. However, recruitment in natural populations is highly variable and rarely well described by classical stock–recruitment relationships (SRRs). Recent analyses suggest that the age composition of the spawning biomass may play an important role in the mismatch between SRRs and data. Here we develop a generalization of the Ricker SRR that incorporates age structure by allowing mortality and fecundity rates to depend on maternal age. We provide a flexible SRR with biologically interpretable parameters that can be estimated from existing fisheries time series and use a Bayesian framework that enables parameters to be informed by experimental data. We apply our method to the Icelandic population of Atlantic cod ( Gadus morhua ) and show models that include age structure effects outperform the classical Ricker SRR that ignores age structure. Our results indicate a strong effect of spawning stock age structure on recruitment dynamics in this population. Our approach provides a biologically interpretable and immediately applicable method for investigating the consequences for spawning stock age structure on recruitment.

Effects of LED light quality on the growth, metabolism, and energy budgets of Haliotis discus discus

Aquaculture ◽  
2016 ◽  
Vol 453 ◽  
pp. 31-39 ◽  
Author(s):  
Gao Xiaolong ◽  
Zhang Mo ◽  
Li Xian ◽  
Shi Ce ◽  
Song Changbin ◽  
...  
Keyword(s):  
Light Quality ◽  
Energy Budgets ◽  
Led Light ◽  
Haliotis Discus ◽  
Growth Metabolism

Bioenergetics of a Sand Goby (Gobius minutus) Population

1972 ◽  
Vol 29 (2) ◽  
pp. 187-194 ◽  
Author(s):  
M. C. Healey
Keyword(s):  
Oxygen Consumption ◽  
Natural Populations ◽  
Somatic Growth ◽  
Energy Budgets ◽  
Sand Goby ◽  
Ingestion Rates ◽  
Active Metabolism ◽  
Gonad Growth ◽  
Parameters Analysis ◽  
Routine Metabolism

This paper describes utilization of ingested energy by a population of sand gobies (Gobius minutus) in the Ythan estuary, Scotland, from November 1966 to March 1969. After metamorphosis (July) the gobies survived about 22 months, and their life could be divided into five stages: somatic growth (July–November); gonad growth (November–February); reproduction (February–June); more somatic growth (June–October); and further gonad growth (October–December). I calculated energy budgets for each stage from the relation:[Formula: see text]where: I = ingested calories; M = calories of metabolism; G = calories of growth.Since I had measures of ingestion, growth, and routine oxygen consumption, I hoped to predict active metabolism by the energy ingested not accounted for in growth and routine metabolism. In fact, 0.8I either equalled the sum of growth and routine metabolism or was much too little to explain predicted expenditures for these parameters. Analysis of published feeding and growth studies in fish indicated that energy imbalances of this sort at low rations are general and that fish seem able to shunt more energy into growth when on a restricted ration than one would predict from studies of standard oxygen consumption. This result together with earlier analyses of Paloheimo and Dickie (1966) indicate that energy budgets for natural populations not based on accurate natural ingestion rates are at best only crude approximations.

scholarly journals Genomic basis of fishing-associated selection varies with population density

2021 ◽  
Vol 118 (51) ◽  
pp. e2020833118
Author(s):  
Amélie Crespel ◽  
Kevin Schneider ◽  
Toby Miller ◽  
Anita Rácz ◽  
Arne Jacobs ◽  
...  
Keyword(s):  
Environmental Factors ◽  
Population Density ◽  
Brain Function ◽  
Natural Populations ◽  
Phenotypic Selection ◽  
Selective Pressures ◽  
Experimental Fish ◽  
Growth Metabolism ◽  
Evolutionary Consequences ◽  
Genomic Basis

Fisheries induce one of the strongest anthropogenic selective pressures on natural populations, but the genetic effects of fishing remain unclear. Crucially, we lack knowledge of how capture-associated selection and its interaction with reductions in population density caused by fishing can potentially shift which genes are under selection. Using experimental fish reared at two densities and repeatedly harvested by simulated trawling, we show consistent phenotypic selection on growth, metabolism, and social behavior regardless of density. However, the specific genes under selection—mainly related to brain function and neurogenesis—varied with the population density. This interaction between direct fishing selection and density could fundamentally alter the genomic responses to harvest. The evolutionary consequences of fishing are therefore likely context dependent, possibly varying as exploited populations decline. These results highlight the need to consider environmental factors when predicting effects of human-induced selection and evolution.

Respiration Rates, Energy Budgets, and Molting Frequencies of Three Species of Euphausiids Found in the Gulf of St. Lawrence

1976 ◽  
Vol 33 (11) ◽  
pp. 2568-2576 ◽  
Author(s):  
D. D. Sameoto
Keyword(s):  
Water Temperature ◽  
Natural Populations ◽  
Energy Budgets ◽  
Lawrence Estuary ◽  
Temperature Changes ◽  
Intermolt Period ◽  
Respiration Rates ◽  
Different Temperatures ◽  
Total Body ◽  
St Lawrence Estuary

Respiration rate experiments at different temperatures were conducted on three species of euphausiids, Meganyctiphanes norvegica, Thysanöessa raschii, and T. inermis, found in the Gulf of St. Lawrence. The slopes of the respiration regression lines at different temperatures for the same species were not significantly different. Thysanöessa inermis acclimated to temperature changes with the result that its respiration rates remained relatively stable over most of the temperatures tested.Feeding rates were measured for M. norvegica and T. inermis at different temperatures using Artemia nauplii as food. The number of calories ingested, expressed as a percentage of the total body calories of the euphausiid, decreased with body size and water temperature. Thysanöessa inermis ingested fewer calories than M. norvegica in relation to total body calories at all temperatures. Both species showed a linear relationship between molting frequency and water temperature, T. inermis having a shorter intermolt period than M. norvegica.Results were used to estimate the energy consumption of the natural populations of euphausiids in the upper part of the Gulf of St. Lawrence estuary.

A model for categorical length data from groundfish surveys

2004 ◽  
Vol 61 (7) ◽  
pp. 1135-1142 ◽  
Author(s):  
Birgir Hrafnkelsson ◽  
Gunnar Stefánsson
Keyword(s):  
Gadus Morhua ◽  
Atlantic Cod ◽  
Length Distribution ◽  
Multinomial Distribution ◽  
Covariance Structure ◽  
Correlation Coefficients ◽  
Estimation Procedure ◽  
Multinomial Model ◽  
Multivariate Gaussian Distribution ◽  
Length Data

An extension of the multinomial model of counts is presented to account for overdispersion and different correlation structure. Such models are needed in biological applications such as the analysis of length measurements from surveys of heterogeneous populations used for assessments of marine resources. One of the goals of such a survey is to estimate the length distribution of each species within a particular area. Using data on Atlantic cod (Gadus morhua) in Icelandic waters, it is demonstrated that the assumptions used in practice for categorical length data are seriously violated. The length data on cod exhibit variances that are larger than those of the standard multinomial model and correlation coefficients that are greater than those of the Dirichlet-multinomial model. To alleviate these problems, a hierarchical model based on the multinomial distribution and the logistically transformed multivariate Gaussian distribution is proposed. It is illustrated that this model captures the complex covariance structure of the data. The parameters in the models are estimated using a Bayesian estimation procedure based on Markov chain Monte Carlo.

High-voltage electron microscopy of maxillary gland of spirochete-infected brine shrimp: lesion of efferent tubule

1988 ◽  
Vol 46 ◽  
pp. 362-363
Author(s):  
G. E. Tyson ◽  
M. J. Song
Keyword(s):  
Electron Microscopy ◽  
High Voltage ◽  
Brine Shrimp ◽  
Natural Populations ◽  
Three Dimensional ◽  
Dimensional Structure ◽  
High Voltage Electron Microscopy ◽  
Voltage Electron ◽  
High Voltage Electron ◽  
Infected Adult

Natural populations of the brine shrimp, Artemia, may possess spirochete- infected animals in low numbers. The ultrastructure of Artemia's spirochete has been described by conventional transmission electron microscopy. In infected shrimp, spirochetal cells were abundant in the blood and also occurred intra- and extracellularly in the three organs examined, i.e. the maxillary gland (segmental excretory organ), the integument, and certain muscles The efferent-tubule region of the maxillary gland possessed a distinctive lesion comprised of a group of spirochetes, together with numerous small vesicles, situated in a cave-like indentation of the base of the tubule epithelium. in some instances the basal lamina at a lesion site was clearly discontinuous. High-voltage electron microscopy has now been used to study lesions of the efferent tubule, with the aim of understanding better their three-dimensional structure.Tissue from one maxillary gland of an infected, adult, female brine shrimp was used for HVEM study.

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