Do fish eat snails?
Yes I am sure that your tandanus catfish are eating the snails. They are solely meat eaters and will eat smaller fish too when they are larger. They do have the strength to suck snails out of the shells besides eating the eggs. There is really nothing that you can do to discourage them from eating the snails or their eggs. I don’t know how much you feed them already but even if you feed them more I am sure they would still go after the snails. This is the nature of these carniverous scavengers and snails are tasty treats to them. None ot the other species of fish in your tank will eat the snails. If you would rather have the snails I would get rid of the tandanus but within a month or so you may find yourself completey overrun with them. I don’t know what kinds of snails you have, some are plant friendly and helpful and others are destructive and can be considered pests. It can be nice to have a snail predator in a tank to keep snail populations under control.
