Systematic studies on the performance of fish as snail eaters in waterbodies are rare. Here, trials with a promising African cichlid (Astatoreochromis alluaudi) revealed that the fish were only successful at reducing snail populations if there was nothing better to eat - and this is hardly the case. The fish need solid jaws to crush the snails but do not develop such jaws if they can find other, preferables foods. The prospects for this form of control are also discussed in the broader context.