Do cephalopods and larvae of other taxa grow asymptotically
Article Abstract:
Many species reaching the end of a life-history stage at relatively fixed sizes grow nonasymptotically before transforming. This pattern is followed by several squid species and some of the larval frogs, fishes, and insects. The data on body size at a range of ages available for these taxa are described by exponential curves or by power curves that are concave upward. These data, when transformed to mean sizes for ages or age classes, may fit the asymptotic growth models of the logistic and Gompertz curves. These curves describe the behavior of the population mean, but fail to describe the pattern followed by any individual in the population. The analysis and presentation of data on size at age using mean sizes may result in wrong interpretations of growth patterns.
Publication Name: The American Naturalist
Subject: Earth sciences
ISSN: 0003-0147
Year: 1993
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To grow or not to grow: optimal resource allocation for Daphnia
Article Abstract:
Resource allocation patterns optimizing fitness in a Daphnia growth and reproduction model are analyzed to determine conditions favoring growth after reproductive maturity. Growth, reproduction and mortality models for Daphnia were constructed and resource allocations calculated. Concurrent allocation of resources to reproduction and growth was observed in the instar before and after reproductive maturity. Growth after maturity, however, varied with respect to survival rate, net production, predation and reproductive life span.
Publication Name: The American Naturalist
Subject: Earth sciences
ISSN: 0003-0147
Year: 1992
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Studying the dynamics of structured population models: a versatile technique and its application to Daphnia
Article Abstract:
The escalator box car train mathematical model is used to analyse population dynamics which are defined by physiological traits. The model integrates the Leslie matrix models with the continuous-time models. This mathematical derivative is used to compute the dynamics of a Daphnia population. Analysis shows that feeding, growth and reproduction is dependent on food density and individual size. This relationship has both stabilizing and destabilizing effects on the population dynamics.
Publication Name: The American Naturalist
Subject: Earth sciences
ISSN: 0003-0147
Year: 1992
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