I haven't kept Paguristes cadenati either unfortunately - it's still on my to-do list of hermit species to investigate further. I only have very general observations about the species. Unfortunately, there's also a lot of conflicting info out there on it.
However, as far as snails go, there's a pretty simple set of rules for hermits and snails that (baring some kind of a miracle-worker of a hermit crab or a very sickly snail) will result in a safe combination. This is over-generalized, but here goes:
- If the hermit is "large" and will be living in a shell up to or over ~2.5"/6-7cm, you'll probably need to write most snails off of the stocking list to be sure you don't run into issues. One exception I've seen is adult Clibanarius vittatus, which seems to ignore even pretty small Nassarius species. I suspect this is becuase Nassarius are too small to fall within the size range of interest for the adult hermits. I don't know whether this would hold for other large species. At any rate, hermits of this size don't usually belong in the average reef tank anyway due to their ability to generally rip things apart.
- If the hermit is small or medium-sized and has a large claw/claws that look like they could open cans, don't give it any snail-shaped cans of the right size. Snails that would fall prey to such a claw include Nerites, Margarites species, Astrea, and very small Trochus. Snails that are significantly larger than the hermit will be safe.
- If the hermit will stay "small" with a <1"/2.5cm shell usualy, such as small Clibanarius species (perhaps P. cadenati...although I've seen some pretty massive individuals), stock snails with shells >1" that have a thick operculum. The snails are an armored tank and out of the range of shell size that would be of interest to the hermit. Any small Clibanarius that can take out a healhty Turbo several times its size probably deserves an award for ingenuity.
It will also remain on the sandbed as they seem to have an inability to climb.
I've had conches climb up to some pretty interesting places, and also go bombing off of some pretty interesting high places. Lack of climbing is not something to count on, especially if there are fragile things that could be landed on. It's more of an issue for "small" fighting conches than larger species, since the weight of the shell starts to affect climbing ability - although even pretty large conches can climb by hopping as though they're going up stairs. My current conch would also appear partway up some rough but nearly vertical surfaces when it was smaller.
Also, nagytamas - I do have your e-mail. I would have gotten to it before getting to this thread actually, but it apparently landed in my spam box for some strange reason and I only just saw it before I was about to hit the "add reply" button here. Sorry about that!
