Substitution of valuable fishery species with those of lower value is common practice because it is easy andoffers immediate financial rewards. Generally, the species used insubstitutions have lower values than those declared on the label,as shown in this study. In particular, the study showed widespreaduse of species of lower commercial value and from highly pollutedwaters in African countries and on the Mekong river in Asia, i.e. L.niloticus and P. hypophthalmus, respectively