We estimated genetic parameters of feed conversion ratio (FCR) and daily growth coefficient (DGC) using individual phenotypes measured in aquariums under a restricted feeding regime and genomic information on 2,722 SNP markers. The results showed a moderate heritability of both traits (0.26 for FCR and 0.41 for DGC) as well as close to unity negative genetic correlation between them. Thus, FCR of fish in aquariums could be improved by selecting fish for higher DGC. Nevertheless, these results must be taken with caution until we know whether individual FCR measured in aquariums also reflects the FCR of fish reared in groups.