Feeding fish with diets of different ratios of C3- and C4-plant-derived ingredients: a laboratory analysis with implications for the back-calculation of diet from stable isotope data.
Rapid Commun Mass Spectrom
; 18(18): 2087-92, 2004.
Article
em En
| MEDLINE
| ID: mdl-15317048
ABSTRACT
Back-calculation of the diet is one of the most frequent applications of stable isotope techniques in animal ecology. These calculations are often based on two assumptions a constant trophic shift for all dietary items and a linear response of the isotopic ratios to different mixtures of two isotopically distinct feeds. In a laboratory experiment, fish (Nile tilapia, Oreochromis niloticus) were fed semi-synthetic diets prepared either from wheat or corn ingredients, or from three blended diets (25, 50, 75% wheat components). Isotopic analysis of the lipid-free and lipid fraction of the fish after the experiment revealed that the trophic shift was not constant for wheat- and corn-based diets. The isotopic response to the mixed diets was not linear, leading to a statistically significant over-estimation of the corn component in the back-calculation. Both effects are in agreement with published data on the isotopic effects of C3- and C4-plant materials in the diet.
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Base de dados:
MEDLINE
Assunto principal:
Isótopos de Carbono
/
Extratos Vegetais
/
Suplementos Nutricionais
/
Ciclídeos
/
Dieta
/
Análise de Alimentos
Tipo de estudo:
Evaluation_studies
Idioma:
En
Revista:
Rapid Commun Mass Spectrom
Ano de publicação:
2004
Tipo de documento:
Article
País de afiliação:
Alemanha