crabs or no crabs that is the question

zabjeff

New member
my hermits keep attacking my snails and i assume eating them. then the hermit population declines, i assume they are eating each other. started with 30 of each and now im down to one each and at the moment he is trying to capture my last snail. i keep replacing them but its the same cycle. maybe the hermits arent getting enough to eat? or is this normal?
 
i had a hermit doing the same thing....he was the only one doimg it hough....... eventually the snail died and the crab took his shell. i dont know if thats why he was doing it or what but after that he never bothered my snails again so maybe you could get some larger shells for him....
 
Hi,

Hermits will eat both algae & anything else they can get their claws into. After a few years of watching this I think it best to decide if you want hermits or snails in your tank. Usually the snails lose if you mix them in a tank. From what I hear the red legged & the scarlet ar less agressive than the blue legs.

Dave
 
They are fine together provided one thing.
You have to remove the hermits once they get big. Basically anything larger than 1 by 1 CM at the opening of the shell is a good rule of thumb I have noticed. Once they get larger than that...they predate upon the snails and on any thing smaller than they are. Or if they decide they want that shell as opposed to the 4 or 5 empty ones near the one with something alive in it of the same apparent size. Go figure.
 
I have had much better luck with scarlets than reds or blues regardless of size.

Right now in my 30 I have a single scarlet that is rather large but leaves the snails alone.
In my 240 I keep snails and emeralds with no hermits for the above reasons

crabs are generally not to be trusted with snails and similars. Emeralds are the only ones I have never seen in a tank without at least a few dead snails.

another option I have considered but never tried is crab dominated (algae controlers) with only those tiny snails (their name escapes me at the moment). Of course since you are not feeding them buck a piece snails you will have to give them some empty shells.
 
I have kept crabs and snails together for years. The key is to keep a close eye on your tank & when you see a snail has fallen and flipped, you must flip it back over before the crabs eat it. You will not always catch them in time, so plan on constantly replacing some snails. I've never seen crabs eat a healthy snail unless it's flipped over.
 
Part of the confusion comes from the fact that:

1) Things die or get sick in your tank for lots of reasons, and
2) Scavengers will eat those things

The result is that you are going to see scavengers, like crabs, eating things like snails, utterly regardless of whether or not the scavengers actually sought them out and attacked them in the first place. I've seen my nassarius snails eating another dead/dying snail (dying, unfortunately, from species/temperature incompatibility, I believe, and regret) right alongside a hermit.

Of course, that doesn't mean that crabs are always innocent. It just means that you might get some false positives when looking for acts of crab predation.

If you want to 100% assure that your snails won't get killed, then don't keep crabs, because as far as I know, there just isn't such a thing as a safe, non-predating crab (not even emeralds, though again, it's all relative, and many people keep them without any aggressiveness at all). But by and large, hermits won't kill snails unless the snails are weak or otherwise compromised to begin with, or the hermits have a decent reason like a) needing a new shell and not having any that are the right size or b) aren't getting enough regular scavenging pickings.

CleveYank is also dead on about simply removing hermits (sticking them in a non-pump intake populated section of your sump or in a running quarantine tank, etc.) when they get big enough to be a serious threat to snails. You could also potentially keep them in your fuge, honestly, since they don't really prey on the particular things most people are seeking to provide "refuge" for in the first place (i.e. sand bed critters, micro crustaceans, live shrimp, etc.)
 
Back
Top