Musical Shells

[jburgi]

So I have 3-5 red leg hermits, 2-3 blue leg hermits-They are from my original CUC that I purchased about 7 mo ago. About 2 months ago I added 3 scarlet hermits, a bunch of nassarius snails, and a couple turbo snails.

ANYWAY...So over the past couple weeks I have noticed that most of my crabs are changing shells. I am not talking about the usual upgrade to a larger shell....some are even downsizing! One of the scarlets moved into a shell that is about a third the size of the original shell! I thing they have killed most/all the nass snails. The blue leg herms are in those shells, and at least half of the red legs are also in nass shells now. One of the turbos died...not sure if it was crab related, the second scarlet tried to move into the shell about a week later...but I think it was too big for it because it never moved from the one spot, then moved back into the old shell by the next day, and is now in a different smaller shell. The third scarlet has tried both of the other 2 old scarlet shells...but now its back its original...and has been in the current shell for a few days.

So is this normal hermit behavior? The only thing that has been changed in a month is that I got rid of a trigger that was terrorising my tank (left the fish and verts alone, but knocked my rocks around and ate coral).

Salinity: .024
Ammonia: 0
Nitrates: 0
Nitrites: 0
pH: 8.0-8.2

Thanks everyone

 

[BallinCrew10]

I know it is normal for hermits to change shells, killing snails if not supplied with empty ones, free meal and a home. As far as them downsizing, I'm not sure. Did you have various size empty shells in your tank for them? This is why I went with emerald crabs, they're cooler and mine have never killed anything lol.

 

[bighabeeb]

I had similar issues first time around when I added hermits to my tank. Killed off a bunch of my snails etc.

Only positive to it was that it made for plenty of empties for the second try - I now have around a dozen hermits living in various snail shells that were in the tank.

 

[jburgi]

I already had various empty shells in the tank. Most of them slightly bigger than the ones they already occupied...but a handful none the less. It is funny to watch them change shells! So meticulous!

I also have 2 emerald crabs! They are sooo cute, and have the funnest personalities