Sorry, I meant that for the OP. I was curious how long they have had it since it would take time to get to 1". I have these guys and the nassarius vibex. This doesn't look anything like the vibex to me...
I just found him in the frag tank which has been running for about a year. I think he is a cantharus snail. I found one that looks just like him when doing a search thanks to iyachtuxivm. Hes predatory to clams which is my concern cause I just got a nice clam for my display and maybes theres is some of them in the display. Hope not, but I'll be watching.