Open AccessNutrient Assimilation by First‐Feeding African Catfish, Clarias gariepinus , Assessed Using Stable Isotope Analysis
Author(s) -
Enyidi Uchechukwu,
Kiljunen Mikko,
Jones Roger I.,
Pirhonen Juhani,
Vielma Jouni
Publication year - 2013
Publication title -
journal of the world aquaculture society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.655
H-Index - 60
eISSN - 1749-7345
pISSN - 0893-8849
DOI - 10.1111/jwas.12016
Subject(s) - clarias gariepinus , catfish , biology , ingredient , assimilation (phonology) , fish meal , zoology , nutrient , meal , larva , soybean meal , food science , fishery , botany , fish <actinopterygii> , ecology , raw material , linguistics , philosophy
Knowledge of ingredients assimilation and biomass contribution to recipient fish is important in feed formulation. The stable isotopes of 13 C and 15 N were used to investigate the assimilation and biomass contribution of bambaranut, Voandzeia subterranea , meal ( BNM ), corn, Zea mays , meal ( CM ) and fish meal ( FM ), in FM substituted diets of first feeding African catfish, Clarias gariepinus , during a 30‐d experiment. The catfish larvae were stocked at 40 fish/ 15 L three replicate glass aquaria. Larvae were fed with experimental diets varying FM , BNM , and CM . Proportions of FM : BNM : CM in the experimental diets were: feed 1 ( F1 ) 60:20:20; feed 2 ( F2 ) 40:40:20; feed 3 ( F3 ) 20:60:20; and feed 4 ( F4 ) 20:20:60. Feeds and larval stable isotopes of δ 13 C and δ 15 N were analyzed. Larval specific growth rates ( SGRs ) were high, enhancing incorporation of dietary δ 13 C and δ 15 N . The SGR was highest for catfish fed F1 and F2 but significantly lower for those on F3 and F4 . Results of δ 13 C and δ 15 N analyses showed that the biomass contribution from FM was similar to BNM , which were better than CM at equal inclusion levels. The nitrogen contribution per ingredient to larval somatic crude protein was increasing with increases in ingredient inclusion and assimilation. Stable isotope analysis is useful for analyzing assimilation and utilization of nutrients.