Snail - Fungus On Shell

I've had algae on a snail shell before, beard algae so tough to remove. That was green though and yours in white... nothing more than that thou I've never had massive success with snails to be honest, apart from the pest variety! I never get long out of them...

Thanks, both. @Sue - my tiger nerite was near the top of the tank late this morning so I decided to have another go with the toothbrush and then, if no success, lift him out as per your suggestion. As it happens, unlike yesterday, I managed to brush off the fungus. I'm not sure I've managed to do that completely - there's a sign of something in a couple of places in the crack in his shell, which very possibly could be food that's got under the shell or in the crack and remains there (or is it possible that the shell could be trying to heal?). I'll monitor the situation over the next few days and, if need be, will remove him and see if I can do a better job with a fingernail if required.

That's an interesting insight that you've not actually noticed an ailment as such that accounts for a snail's demise. I know some of yours have lasted many years. This one is nearly 2.5.  He had been going through a spell lately of falling off the glass several times a day, which I had wondered was a sign of his potential demise, but I've also noticed that one of my tetras (who I think is now blind) poked at him a few times until he fell off and I'm wondering how many of the snail's falls can be accounted for by that. The other nerite is a lot bulkier and possibly too difficult to dislodge from her position although she's more usually to be found on the wood, under the filter or above the waterline (as opposed to on the glass).

I've had 3 - one is almost 2.5, one is 1.25 but the little one was dead within a few days of entering the tank (it accompanied the second nerite but the journey must have taken its toll). I've bought mine online from the same place, in the spring/summer months. If you do get a horned nerite, then I'd probably advise not buying it online during the winter months - not sure it would survive the cold temperatures overnight in a postal delivery office. It might also be worth getting Shrimp King Snail Stixx which I feed mine on (in addition to their algae/wood munching).