Seasonal variations in ectotherm growth rates: Quantifying growth as an intermittent non steady state compensatory process

Journal of Sea Research
By: , and 

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Abstract

Generally, growth rates of living organisms are considered to be at steady state, varying only under environmental forcing factors. For example, these rates may be described as a function of light for plants or organic food resources for animals and these could be regulated (or not) by temperature or other conditions. But, what are the consequences for an individual's growth (and also for the population growth) if growth rate variations are themselves dynamic and not steady state? For organisms presenting phases of dormancy or long periods of stress, this is a crucial question. A dynamic perspective for quantifying short-term growth was explored using the daily growth record of the scallop Pecten maximus (L.). This species is a good biological model for ectotherm growth because the shell records growth striae daily. Independently, a generic mathematical function representing the dynamics of mean daily growth rate (MDGR) was implemented to simulate a diverse set of growth patterns. Once the function was calibrated with the striae patterns, the growth rate dynamics appeared as a forced damped oscillation during the growth period having a basic periodicity during two transitory phases (mean duration 43. days) and appearing at both growth start and growth end. This phase is most likely due to the internal dynamics of energy transfer within the organism rather than to external forcing factors. After growth restart, the transitory regime represents successive phases of over-growth and regulation. This pattern corresponds to a typical representation of compensatory growth, which from an evolutionary perspective can be interpreted as an adaptive strategy to coping with a fluctuating environment.

Publication type Article
Publication Subtype Journal Article
Title Seasonal variations in ectotherm growth rates: Quantifying growth as an intermittent non steady state compensatory process
Series title Journal of Sea Research
DOI 10.1016/j.seares.2011.02.001
Volume 65
Issue 3
Year Published 2011
Language English
Publisher Elsevier
Contributing office(s) Toxic Substances Hydrology Program
Description 7 p.
First page 355
Last page 361
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