Stable isotope profiling of farmed Penaeus monodon for the evaluation of feed efficiency

Abstract

Abstract The current study profiled the dual isotopes of carbon and nitrogen in feeds and muscles of farmed Penaeus monodon for evaluation of feed efficiency in making up the prawn muscle. Signatures of both feed and resulted muscles of P. monodon were subjected to two‐ and three‐source linear mixing models to elucidate the contribution of each feed item in the building of the muscle. The results revealed that carbon and nitrogen in different feed substances have different influences on the growth and nutrient uptake by the prawn. Different growth stages showed isotopic switching within prawn muscles in the course of their building up. Generally, marine sources were the most enriched in both δ13C and δ15N. Likewise, δ13C of wild‐caught prawns (−16.30 ± 0.72‰) were superior over farmed prawns (−18.00 ± 0.59‰) (p 0.01). The isotopic composition of P. monodon mirrored those of the ingredients contained in its feed and varied across treatment levels. Comparing to other ingredients, marine macroalgae exhibited significantly higher (p 0.01). Moreover, a clear distinction was observed between wild and farmed P. monodon, and such a distinction is clearly explained by δ13C composition. In conclusion, multiple sources of δ13C and δ15N in feeds are incorporated more efficiently in muscles than single sources.

Keywords

• feed utilization
• growth
• Penaeus monodon