Inverse demand systems explain price variations as functions of quantity variations. This paper presents a dynamic inverse AIDS model based on recent developments on cointegration techniques and error correction model. The case of fish landed at Geek sea ports appears to suit this model well. The results indicate that the underlying distance function is homothetic while the own-quantity flexibilities suggest that the responses of price to own-quantity changes are inelastic. Finally, the results of cross-quantity uncompensated flexibilities suggest that the substitution possibilities among fish grades are rather limited. The Allais interaction intensities verified the substitutability among fish grades as well.