Fish species identification is traditionally based on morphological features but this may be difficult or even impossible in case of processed products or in cod species, which are usually highly similar.

Gadoids (Cod) are a group of fish with historical importance to the fishing industry. The high demand for cod is one of the reasons why cod products are often mislabelled, and numerous incidents have been reported on the replacement of Atlantic cod (Gadus morhua) by cheaper species.

However, traditional fish identification methods may be difficult to use in case of highly processed products such as fish fingers.