They do look like nassarius snails don't they. Although I've since read nassarius snails will definitely not eat algae, so I assume they're dove snails because they swarm when I drop an algae pellet in. Either way, they're great cleanup crew! Breed easily and turn the sand over quite a bit. Can't see any negative effects of having them. With their omnivorous nature I don't know why they're not more popular (probably because lfs wouldn't make much money given how easily they breed). Not sure why ppl would waste money on snails which don't breed vs these little guys (exception being the need for larger snails which clean glass/rocks).They definetly look like nassarius snail and not whelks so ur lucky