Could these be flatworms? Seriously concerned about their numbers... they are all over my rocks. I never noticed them yesterday, they really must have exploded in numbers. My BTA is very angry now, no tentacles at all. Are there pests that attack anemones? I don’t see them ON the anemone but all around it.
YES. Those aren't the ones that eat things, but they'll multiply like nuts and smother. Plus I believe toxins if all killed off fast.
Most probably won't believe it, but I had these bad around a dozen years ago in a 92g. I wouldn't suggest it, but I just left them alone and they eventually just fizzled out. I don't know if it was due to so many generations or what, but I never treated the tank and after a couple of months there weren't any.
However, I'd go with whatever treatment others here have successfully used that worked quickly.