Comparative study on the morphological characteristics and nutritional quality of largemouth bass (Micropterus salmoides) cultured in an aquaculture system using land-based container with recycling water and a traditional pond system

To determine the differences in morphological characteristics and muscle nutritional quality between largemouth bass (Micropterus salmoides) cultured in an aquaculture system using land-based container with recycling water (C-RAS) and those cultured in a traditional pond system (TP), largemouth bass with no significant difference in body weight were selected. Results showed that the largemouth bass cultured in C-RAS had a significantly longer body and significantly lower condition factor and viscerosomatic index than those cultured in the TP (P < 0.01). In terms of muscle characteristics, the water loss and muscle fibre diameter were significantly lower in the C-RAS group than those in the TP group (P < 0.05), whereas the firmness, chewiness, springiness, and shear force in the C-RAS group were significantly higher than those in the TP group (P < 0.01). The crude protein content was significantly higher in the muscles of largemouth bass cultured in C-RAS than in those cultured in the TP (P < 0.05). The crude lipid content was significantly lower in the C-RAS group than that in the TP group (P < 0.01). Among fatty acids, the levels of DHA, sigma n-3, and sigma n-6 were significantly higher in the C-RAS group than those in the TP group (P < 0.01), moreover, delicious amino acid (DAA) levels were significantly higher in the C-RAS group than those in the TP group (P < 0.05). The levels of elements such as K and Na were significantly higher in the muscles of largemouth bass cultured in C-RAS than in those cultured in the TP (P < 0.01); however, the Se content was significantly lower in the C-RAS group than that in the TP group (P < 0.05). Levels of volatile substances such as 2-butanone, benzaldehyde, and pentanal were significantly higher (P < 0.05), whereas the levels of nonanal, octanal, and 2,5-dimethylpyrazine were significantly lower (P < 0.05), in the muscles of largemouth bass cultured in C-RAS than in those cultured in the TP. These results suggest that the culture system significantly affected largemouth bass' morphological and muscular characteristics as well as levels of nutritional components, mineral elements, and volatile substances in the muscle.