Whats wrong with this nassarius snail?

[BloopFish]

This snail has been upside down stretching itself out for the past 24 hours. Even if I right it back up, it'll get back to this position. Every other snail in my tank is fine, including 3 other nassarius snails. I have been feeding general cure binded with focus, but I doubt that's the reason because all my other inverts are fine (porcelain crabs, fire shrimps and sexy shrimps). Before this started to happen, it wouldn't come out of the sand for a week or two after it was first introduced. Any idea on whats wrong?

 

[Billldg]

I have never seen my nassarius snails do that, but I have seen my cerith snails do that. Unfortunately the loss rate for snails is high, some just do better than others, it all depends on where they were caught originally, or if they were tank born over several generations.

 

[Bret Brinkmann]

Pull it out and look for something on it. I wonder if pyramid snails would eat a nassarius...