By the position on the shell, this is definitely a species of parasitic pyramidellid snail. If you search on the Ask Dr Ron forum, he also calls them pyrams.
A Six Line Wrasse supposedly favors small snails. Unless you remove all the animals it can feed on for a few months, you probably can't totally get rid of them.
Manual removal can help. If you remove the snail from the tank, you can wipe the edge of the snail's shell with your finger and give it some relief. If you check all of your snails and clean them, you can cut down on the number of parasites.
I have one tank that has them (they hitchhiked on some live sand I got from someone). Before I remove any snail from that tank, I check each one carefully and pick off the parasites with tweezers. So far, they have not spread to any other tank. In that tank, I have a snail occasionally (maybe once every few months or so) die. Thus, while they are parasites, they don't seem to immediately kill their hosts.
Best of luck,
Roy