Applied Ecophysiology: An Integrative Form to Know How Culture Environment Modulates the Performance of Aquatic Species from an Energetic Point of View - Aquaculture and the Environment: A Shared Destiny - page 186

The GLMM model included the use of a variance and a correlation structure that enhanced
the model fit (the best AIC value was obtained: 251.4), and successfully explained octopus
weight as a function of age. Because the date of hatching was registered for each individual,
“age” is fixed in the model (i.e. it has no associated error), a feature in models fitted by least
squares that is not usually met. According to this model, O. maya juveniles grow at a rate of
0.03 g/day, a rate similar to that obtained for other O. maya cultures (unpublished data). The
δ parameter estimated in 0.204 is the exponent Given the correlation and variance structures
included in the current model, and the parameters associated with them ( δ , range), the
procedures followed to adjust the GLMM model detailed here allow a high level of
precision in predicting octopus weight from known age, thus, making the estimates of
growth rate more reliable than other growth models.
6. Conclusions
During aquaculture technological development of species it is common that farmers or
researchers start the culture only putting some animals in ponds, floating cages, or any other
closed environment giving attention on productive parameters such as growth and survival.
It is also common that, at the beginning of culture, animals are feed with the local available
food in attempt to evaluate if in such conditions animals can be raised. However, this
approach does not allow getting enough information for a sustainable development of
culturing technology. In this sense, ecophysiology can help to evaluate how environmental
conditions modulate several responses of cultured organisms, including the scope for
growth, one of the key parameters involved in the energy balance equation. This model
could be used as a base to make economical inferences or to modify culture methods. As
showed in the present work, independently of the cultured species, the bulk of papers
dedicated to demonstrate the effects of many environmental factors on physiological
condition of animals validate applied ecophysiology as a useful method for the
development and improvement of cultivation technology of aquatic organisms.
7. Acknowledgements
The present chapter is the result of many research made with the financial support of
FONDEF D02i1163, D05i10217, Fondecyt 1110637, FONDEF D09I1153 in Chile and
CONACYT through their financial support to make the sabbatical year of CR and Papiit IN
290327 to CR in Mexico.
8. References
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