This study seeks to identify interproduct relationships between domestic catfish and a representative selection of imported seafood. In doing so, this study uses multivariate cointegration and structural analyses. Multivariate cointegration analysis suggests that six imported seafood product groupings form a common market with domestic catfish. Structural analysis reveals that 1) domestic and imported catfish are net and gross quantity substitutes; 2) domestic catfish and imported seafood are normal goods; 3) six imported seafood products are identified as gross quantity substitutes for domestic catfish; and 4) according to the derived Allais coefficients, interaction intensities of imported seafood for domestic catfish (from greatest to least) are as follows: tuna, shrimp, salmon, tilapia, catfish, and trout.