Dang, I think @ISpeakForTheSeas and @i cant think remember me and won’t be coming to help, sorry @Nor'easter Reefer .
Haha, I'm coming to help, just running chronically behind these days - it's a Volvarina species of some variety (V. taeniolata being mentioned in the thread linked):Thread 'Baby nassarius snail? Pics included' https://www.reef2reef.com/threads/baby-nassarius-snail-pics-included.861347/
Sorry for the delay in my response - most likely a Volvarina species, but there are hundreds of species in the genus and they're not common in the hobby, so I don't know which specific species you have:
I've heard some are basically herbivores, others may be somewhat predatory, but I'd guess that it's more likely to be an omnivorous scavenger for you (shouldn't eat anything live, but may go for something dying) - so I'd say observe it for issues, but probably expect it to be good CUC.Yeah, the closest snails I know are from the same taxonomic subfamily (Marginellinae) as true Marginella spp. snails - I'd guess a Volvarina sp.; these are still known as "Marginella" or "Margin" shells/snails.