These are the same snails I had discussed in a previous thread. They are the common mud snail, Ilyanassa obsoleta, found in all of our bay and salt marsh water, at the shoreline. 5 minutes along any of these shorelines and you can literally pick up dozens...if not hundreds. They are very definitely reef safe and reef hardy. I collect mine from Cutchogue, LI...despite lower salinity and lower temps, I just toss them in the tank without acclimation...being shoreline snails, they are accustomed to major swings in both factors. They last for years. They bury in the sand, and climb the glass....they are excellent scavengers, taking care of leftover food and dead fish. They do not eat algae...and will lay eggs in your tank, usually within hours of being released. I would never buy them...and certainly shouldn't sell for more than $0.50 a piece...as I said any trip to a bay or salt marsh shore could supply all the people on this group from no more than one square meter of shoreline....Take care, Eric