Originally Posted by Bang Guy
Nassarius Snails are actually a type of Whelk...
That's like trying to tell the difference between a Clownfish and a Percula.
from what i can gather though, is nass. snails do not have the black shapes on their snouts, like most reef damaging whelks do. also, whelks don't generally bury themselves in the sand, but hunt the rocks and glass. where nass. snails generally live in the sand and will go up on the glass, but almost never on the rocks.
it is odd though, mark says the whelks keep growing, where as nass. snails don't grow very big. I have 15 tonga nass. snails which are huge (about 5/8" large) but the shells are rounder, and i had some whelks which were huge that the shells were long and oval. i got some nass. snails from this site and they look more like whelks--if they didn't bury themselves they would have been in the fuge.