Yesterday I noticed two ramshorn snails that were upside own. One was small and I could not see much, the other I could clearly see the snail body inside, not moving.
Figured he had fallen and would eventually move.
This morning I looked again, the first small one still no motion, I retrieved it and it was a completely empty shell (quite pretty actually, very translucent). Snail organics completely, totally gone.
The other was overwhealmed by about 5 other Ramshorns, like either a mating or feeding frenzy. I suspect the latter.
I just left it alone to see. There's maybe 10 snails in the tank, so it's unusual I think for two to die at the same time, but the others look healthy and happy (as do the rest of the inhabitants). Normal water chemistry, though I did just do an (infrequent) water change the same day these died (I let nitrates get to maybe 40 or so, then do a water change -- it's a planted tank so the nitrates grow slowly).
water, remineralized to dGH=5 or so, dKH
=7 or so (a bit higher, it never quite comes out on target), ph 7.6.
I'm less curious what killed them (well, until there are more), than where the body went -- do snails scavenge their own?
Or could one of the fish have done it (congo tetra, serpae tetra, raphael catfish and BN pleco). I assume the catfish will eat most anything but doubt he would leave the shell? The shell is perfect looking, not crushed or anything.
My guess is they died, and the other snails ate the body?