| Autor: |
De Graaf, Gertjan, Prein, Mark |
| Předmět: |
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| Zdroj: |
Aquaculture Research; Jan2005, Vol. 36 Issue 1, p100-109, 10p |
| Abstrakt: |
Three approaches for multivariate analysis of fish growth in aquaculture experiments with Nile tilapia (Oreochromis niloticus niloticusL.) based on the von Bertalanffy growth curve are presented and compared. The approaches are: an extended Gulland-and-Holt (GH) plot, a forced extended GH plot and a multilinear regression analysis for the growth parameter K. All three models provide valuable insight into the major environmental factors influencing the daily growth rate and explain 28–46% of the variance of the observed daily growth rate of the used data set. For all three methods, the modelled parameter is significantly related to the net yield of Nile tilapia and can, therefore, be used for the predictive modelling of management scenarios. The extended GH plot loads the influence of environmental parameters uponL∞, while the forced extended GH plot and Direct fitting ofKload the influence on the growth parameterK. The latter is more in the tradition of aquaculture research. But the forced extended GH plot and Direct fitting ofKcan only be applied ifL∞ of the cultured species is known, as the selectedL∞ influences the variance in the regression variables. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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