They look to be planorbids, or Ram's Horn snails, but it would be tough to ID to the species level from that pic (or any single pic of a live snail, actually). Scroll down to #78, Planorbidae, on this link and see if you can separate yours:
They look to be planorbids, or Ram's Horn snails, but it would be tough to ID to the species level from that pic (or any single pic of a live snail, actually). Scroll down to #78, Planorbidae, on this link and see if you can separate yours: