Now this seems like it could be the best candidate. My tank is stocked with a ton of macro algae & plants I collected in the Florida Keys about a month ago. Looks like Marginella are native to the Keys, so I might have brought some eggs back in the plants/macros. I was leaning toward Nassarius, but I’ve only had adult Nassarius in the tank for a week so the timeline just doesn’t add up. Will keep you guys updated.