INDIVIDUAL VARIATION OF GROWTH AND FILTRATION RATES OF MUSSELS MYTILUS GALLOPROVINCIALIS LAM

2017 ◽  
Author(s):  
Irina Kazankova ◽  
Irina Kazankova ◽  
Elena Vasechkina ◽  
Elena Vasechkina
Keyword(s):  
Growth Rate ◽  
Individual Variation ◽  
Coefficient Of Variation ◽  
Individual Variability ◽  
Individual Growth ◽  
Rate Variation ◽  
Sample Mean ◽  
Metabolic Costs ◽  
Individual Growth Rate ◽  
The Mean

Research on individual variation of the filtration and growth rates of mussels was based both on the authors’ field and laboratory experiments and literature data analysis. High individual variability of these characteristics was recorded during the tests. The coefficient of variation grew up as the mean rate diminished. Under low specific growth rate the coefficient of variation (ratio of root-mean-square deviation to the sample mean) could exceed 100 %. Tests revealed the power-law relation of the coefficient of variation from the average for studied characteristics. That relation could be seen in filtration and growth rate charts; it was also true for estimates of production energy and metabolic costs. The exponent varied from -0.36 to -0.77. Individual growth rate variation of mussels was concluded to be an important criterion of the favorability of environmental conditions.

INDIVIDUAL VARIATION OF GROWTH AND FILTRATION RATES OF MUSSELS MYTILUS GALLOPROVINCIALIS LAM

2017 ◽  
Author(s):  
Irina Kazankova ◽  
Irina Kazankova ◽  
Elena Vasechkina ◽  
Elena Vasechkina
Keyword(s):  
Growth Rate ◽  
Individual Variation ◽  
Coefficient Of Variation ◽  
Individual Variability ◽  
Individual Growth ◽  
Rate Variation ◽  
Sample Mean ◽  
Metabolic Costs ◽  
Individual Growth Rate ◽  
The Mean

Research on individual variation of the filtration and growth rates of mussels was based both on the authors’ field and laboratory experiments and literature data analysis. High individual variability of these characteristics was recorded during the tests. The coefficient of variation grew up as the mean rate diminished. Under low specific growth rate the coefficient of variation (ratio of root-mean-square deviation to the sample mean) could exceed 100 %. Tests revealed the power-law relation of the coefficient of variation from the average for studied characteristics. That relation could be seen in filtration and growth rate charts; it was also true for estimates of production energy and metabolic costs. The exponent varied from -0.36 to -0.77. Individual growth rate variation of mussels was concluded to be an important criterion of the favorability of environmental conditions.

scholarly journals Growth Rate Variation and Larval Survival: Inferences from an Individual-Based Size-Dependent Predation Model

1993 ◽  
Vol 50 (1) ◽  
pp. 133-142 ◽  
Author(s):  
James A. Rice ◽  
Thomas J. Miller ◽  
Kenneth A. Rose ◽  
Larry B. Crowder ◽  
Elizabeth A. Marschall ◽  
...  
Keyword(s):  
Growth Rate ◽  
Growth Rates ◽  
Individual Variability ◽  
Individual Growth ◽  
Rate Variation ◽  
High Survival ◽  
Initial Growth ◽  
Size Dependent ◽  
The Mean ◽  
Selection For

We used an individual-based Monte Carlo simulation model to explore how changes in the mean and variance of growth rates of individuals in a larval fish cohort interact with size-dependent predation to affect the number and characteristics of individual survivors. Small changes in initial cohort mean growth rate can change survival over the first 60 d of life 10-to 30-fold. But when variance in growth rate among individuals is high, survival can be substantially higher than expected from the initial mean cohort growth rate. Selection for faster-growing individuals becomes stronger with increasing variance and increasing predation rate. In some cases, > 80% of the survivors may come from the upper 25% of the initial growth rate distribution, and the mean growth rate of the survivors may exceed twice the initial mean growth rate. When individual growth rates change from day to day rather than remaining constant, the contribution of atypical individuals is accentuated even further. Counterintuitively, most of the selection for faster-growing individuals happens only after the majority of mortality has already taken place. These results suggest that interactions between individual variability and selective mortality may have important cohort-level implications for survival in fishes.

Demography of an Estuarine Amphipod (Gammarus lawrencianus) Experimentally Selected for High "r": A Model of the Genetic Effects of Environmental Change

1981 ◽  
Vol 38 (9) ◽  
pp. 1120-1127 ◽  
Author(s):  
R. W. Doyle ◽  
W. Hunte
Keyword(s):  
Growth Rate ◽  
Population Growth ◽  
Life History Strategy ◽  
Intrinsic Rate ◽  
Individual Growth ◽  
Population Growth Rates ◽  
Phenotypic Correlations ◽  
Demographic Traits ◽  
Marine Crustacean ◽  
Individual Growth Rate

The estuarine amphipod Gammarus lawrencianus was subjected to prolonged selection (3 years; 26 generations) for high population growth rates. The demography of the selected population was studied in detail and compared under laboratory conditions with animals derived from a control (wild) population collected in the same area 3 years later. In the lab-adapted population the intrinsic rate of population growth r increased by 72% as the result of changes in age at maturation, survivorship, and fecundity. The variance of these traits decreased and Crow's (1958) index of total selection (variance of fitness/mean fitness squared) is proposed as a quantitative and operational measure of genetic adaptation to a changed environment. Possible limitations on adaptation were investigated by examining the correlations among demographic traits within the lab-adapted population. Some phenotypic correlations were determined directly and others by an indirect technique using information from full siblings. Individual growth rate was negatively correlated both with survival and fecundity. Individual growth rate and age at sexual maturity were also negatively correlated. Negative phenotypic correlations between traits may indicate limitations on long-term adaptation. We conclude that significant evolutionary changes in the demographic traits of this (and presumably other) marine crustacean can occur within a time scale of interest to ecologists and aquaculturalists.Key words: adaptation, amphipod, aquaculture, Crustacea, evolution, Gammarus, genetics, life history, strategy

Patterns of metamorphic age and length in marine fishes, from individuals to taxa

2000 ◽  
Vol 57 (4) ◽  
pp. 856-869 ◽  
Author(s):  
Hugues P Benoît ◽  
Pierre Pepin ◽  
Joseph A Brown
Keyword(s):  
Growth Rate ◽  
Population Level ◽  
Individual Variability ◽  
Marine Fishes ◽  
Exponential Relationship ◽  
Factors Affecting ◽  
The Mean ◽  
Time Required ◽  
Increasing Temperature ◽  
Dominant Influence

We present a summary of variability in age and length at metamorphosis for marine fishes. Data from the literature were partitioned into taxonomic, population, and individual levels of resolution to examine the factors affecting the timing of metamorphosis. Temperature appears to be a dominant influence on timing, likely due to its effect on growth rate. Interspecifically, length at metamorphosis correlated poorly with that at hatching but was significantly related to temperature. This pattern was inconsistent for population-level comparisons. Metamorphic age decreased exponentially with increasing temperature in interspecific and population-level comparisons but did not covary with length for either level of resolution. This suggests that age at metamorphosis largely reflects the time required to grow to a given metamorphic length. Within populations, the correlation between metamorphic age and length increases with growth rate, a reflection of variance in age and length. A strong exponential relationship between mean metamorphic age and length and their associated variability (SD) exists, with a slope greater than unity in both cases (i.e., variability increases relative to the mean). With these relationships, we can infer the manner in which individual variability in metamorphic traits is generated throughout ontogeny. These results are considered in light of recruitment variability in marine fishes.

Is boldness towards predators related to growth rate in naïve captive-reared Arctic char (Salvelinus alpinus)?

2007 ◽  
Vol 64 (4) ◽  
pp. 665-671 ◽  
Author(s):  
Mika VM Laakkonen ◽  
Heikki Hirvonen
Keyword(s):  
Growth Rate ◽  
Captive Breeding ◽  
Salvelinus Alpinus ◽  
Antipredator Behavior ◽  
Underlying Mechanism ◽  
Arctic Char ◽  
Individual Growth ◽  
Detailed Knowledge ◽  
Individual Growth Rate ◽  
Slow Growing

Previous studies have shown that the antipredator responsiveness of fish degenerates through generations in captive breeding. However, detailed knowledge of the underlying mechanism is still largely lacking. We tested the hypothesis that hatchery fish supposedly selected for faster growth in the hatchery environment are bolder towards predators than their slower-growing conspecifics. This was examined by comparing the antipredator behavior of predator- naïve fast- and slow-growing individuals of a captive-bred Arctic char (Salvelinus alpinus) population to chemical cues from natural predators burbot (Lota lota) and pikeperch (Sander lucioperca). As behavioral responses depended on char body size, we compared boldness towards predators of size-matched fast- and slow-growing char. We found no differences in four behavioral antipredator traits between size-matched groups of fast- and slow-growing char. According to these results, boldness to predator cues is not related to individual growth rate in captive-bred Arctic char.

scholarly journals Individual growth pattern and variability in Serranus scriba: a Bayesian analysis

2009 ◽  
Vol 67 (3) ◽  
pp. 502-512 ◽  
Author(s):  
Josep Alós ◽  
Miquel Palmer ◽  
Salvador Balle ◽  
Antoni Maria Grau ◽  
Beatriz Morales-Nin
Keyword(s):  
Growth Rate ◽  
Bayesian Analysis ◽  
Growth Pattern ◽  
Growth Curves ◽  
Individual Variability ◽  
Growth Patterns ◽  
Individual Growth ◽  
Individual Level ◽  
Population Dynamics Models ◽  
Dynamics Models

Abstract Alós, J., Palmer, M., Balle, S., Grau, A. M., and Morales-Nin, B. 2010. Individual growth pattern and variability in Serranus scriba: a Bayesian analysis. – ICES Journal of Marine Science, 67: 502–512. Variability in growth patterns at an individual level in Serranus scriba is described using a Bayesian approach for a generalized von Bertalanffy growth model that accommodates one change in growth rate at a specific point during the lifespan. The approach enables individual growth curves to be inferred, even in a species with a relatively short lifespan and no commercial value, i.e. limited sample sizes available, but potentially endangered by recreational fishing. The change in growth rate may be the result of differing allocation of energy between reproductive and somatic activities at different ages. Overall, the approach presented provides adequate input for future implementation of population dynamics models that take into account individual variability, e.g. individual-based models, even for species for which limited data are available.

Influence of growth and survival costs of reproduction on Atlantic cod, Gadus morhua, population growth rate

1999 ◽  
Vol 56 (9) ◽  
pp. 1612-1623 ◽  
Author(s):  
Jeffrey A Hutchings
Keyword(s):  
Growth Rate ◽  
Population Growth ◽  
Gadus Morhua ◽  
Atlantic Cod ◽  
Environmental Stochasticity ◽  
Individual Growth ◽  
Growth And Survival ◽  
Individual Growth Rate ◽  
Age Structured ◽  
Reproductive Rates

A stochastic, age-structured life history model was used to examine how age at maturity (theta), pre- (Zimm) and postreproductive (Zmat) mortality, and postreproductive growth rate can affect maximum reproductive rates of fish at low population size. Simulations suggest that annual (r) and per-generation (R0) metrics of population growth for Newfoundland's northern Grand Bank Atlantic cod, Gadus morhua, are primarily influenced by changes to mortality prior to and following reproduction. At observed weights at age and Zmat = 0.2, r ranged between 0.135 and 0.164 for cod maturing at between 4 and 7 years. Incremental increases in either Zimm or Zmat of 0.1 were associated with 0.03-0.05 reductions in r. To effect similar reductions, individual growth rate would have to decline by approximately one half. At observed weights at age, increases in Zmat from 0.20 to 0.45 increased the probability of negative per-generation growth from 3 to 26% for cod maturing at 4 years and from 6 to 46% for cod maturing at 7 years. Thus, even in the absence of fishing mortality, little or no population growth by Atlantic cod may not be unexpected in the presence of environmental stochasticity, particularly when accompanied by increases in mortality and declining individual growth.

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