I have two Super Tongan nassarius snails that I got from liveaquaria.com; cool little buggers!
They almost never go on the rocks at all! They love the sandy bottom, where they bury themselves quite rapidly! The first time I got mine in my tank, I had set it on a rock; it wasnt looking so hot, so I just waited and watched for a while. I had to go get the phone in the other room, and after theyd' hung up (wrong number, like a 6 word conversation), I came back, and the snail was all the way down on the sand, like 8 inches or so away! Then, I looked away for like a minute or something to get a test sample or something like that, and he was gone!!! It just disappeared! Of course, at this point, I hadn't known that they buried themselves... The whole point of this is that if you dont seem em' for a while, more than likely theyve buried themselves right in front the glass! Just look for the little tip of a snorkel poking out of the sand...
Also, they dont really have a strong foot at all; in fact, Id have to say that their grip is one of the weakest! Case in point: whenever they do surface and go about moving like speeding bullets (I swear, fastest snail Ive ever seen, and it wasnt even motivated!), they tend to enjoy trying to scale the glass at break-neck (for a snail) speeds. But, when it looks like theyve changed their minds, they try and maneuver a standing 180 degree turn on the glass. They almost always fall in the middle of such an akward maneuver... Its pretty funny though!
Nassarius snails dont get very big at all; mine are almost full grown at less than an inch (shell length; that foot of theirs stretches out way far!), so their size isnt much to worry about. That, and the fact theyre fairly week for snails, combined with their seeming lack of sense, stupidity, and even a general lack of life-preserving instinct, makes for a generally innefectual chaos causer. None of my corals in those high places are glued down either; the only time a nassarius made it up that far he didnt even make it flinch in its positioning...
So, you see, nassarius snails arent just usefull and safe, but theyre really cool looking and acting creatures to boot!
Hope that helps!
