pagojoe
Team RC
That's a good observation about what's gone on in your tank, but a pretty broad generalization following your observation. I'm not at all sure that "sick," "dying," and "vulnerable" don't smell the same to Nassarius arcularius. (Do stress chemicals from sick animals and stress chemicals from animals being transferred to new tanks smell the same to them?) It very well might be that your Nassarius snails never got very hungry, or that you never had the most vulnerable prey species in your tanks. There are plenty reports on the internet of these snails occasionally attacking animals that were apparently healthy. (When a Harpa snail or Stomatella snail autotomizes its foot, the snail is still healthy, but the effect is the same as if you chopped half its foot off, and the same body fluids will enter the water.) I've personally seen the difference in behavior between well-fed Nassarius snails and starved ones, and the starved ones become noticeably more aggressive. That's why I said it wouldn't surprise me at all if this large species creates its own carrion when it's starving.
Cheers,
Don
