Bully hermit crabs, etc

[jaxteller007]

So it seems like the hermit crabs in my tank are steady bullies. Always picking on either the smaller ones or killing our snails (I assume that's what is killing them as they are all over the snails anytime they are not on the glass). We've started taking the bigger ones out and putting them in our little 10 gallon emergency tank. I'm concerned with not having enough in the tank but at the same time, having to constantly buy new snails is getting old and expensive. We do try and keep empty shells in the tank as well.

These are just your standard small hermits.

Also the gf bought some kind of pulsing coral thingy (without telling me) and yesterday she had to chase the bigger of the 3 emerald crabs we have away from it. She said it was picking at the coral. Is that a known issue with emeralds?

Tank stock right now is 1 sailfin tang, 1 bicolor blenny, 3 firefish, 1 starfish, hermits and snails. At one time I think we had 14 or 15 hermits (75 gallon tank) and 8 or 9 of the glass cleaning snails. Now I think we have 10 hermits and like 4 snails. 3 hermits in the 10 gallon tank and a couple died (don't know if natural causes or from the bigger hermits beating up on them).

 

[Brew12]

So it seems like the hermit crabs in my tank are steady bullies. Always picking on either the smaller ones or killing our snails (I assume that's what is killing them as they are all over the snails anytime they are not on the glass). We've started taking the bigger ones out and putting them in our little 10 gallon emergency tank. I'm concerned with not having enough in the tank but at the same time, having to constantly buy new snails is getting old and expensive. We do try and keep empty shells in the tank as well.

These are just your standard small hermits.

Also the gf bought some kind of pulsing coral thingy (without telling me) and yesterday she had to chase the bigger of the 3 emerald crabs we have away from it. She said it was picking at the coral. Is that a known issue with emeralds?

Tank stock right now is 1 sailfin tang, 1 bicolor blenny, 3 firefish, 1 starfish, hermits and snails. At one time I think we had 14 or 15 hermits (75 gallon tank) and 8 or 9 of the glass cleaning snails. Now I think we have 10 hermits and like 4 snails. 3 hermits in the 10 gallon tank and a couple died (don't know if natural causes or from the bigger hermits beating up on them).

That is pretty common behavior for crabs. It is why some people won't keep any crabs of any type in their reef tanks. If an emerald crab has the choice between eating corals or starving, it will eat corals every time. The only way to get it to stop is to feed it something it like better. And my crabs are not good at ordering off a menu!

 

[OriginalUserName]

To quote the guy from "True Animal Facts". That's how a hermit crab do.

Pulsing zenia?

 

[nautical_nathaniel]

I have had the best luck with the dwarf zebra hermits: https://www.liveaquaria.com/product...ge-black-hermit-crab?pcatid=613&c=497+501+613

They seem to be more mellow and less likely to go after snails in my experience but they will definitely still go after them if they find a weak snail or need a new shell.

 

[jaxteller007]

That is pretty common behavior for crabs. It is why some people won't keep any crabs of any type in their reef tanks. If an emerald crab has the choice between eating corals or starving, it will eat corals every time. The only way to get it to stop is to feed it something it like better. And my crabs are not good at ordering off a menu!

I try to make sure we keep enough stuff at the bottom for them but we will have to monitor this better and just keep an eye on it.

I wonder if it's better to just have a couple hermits and keep more snails. I would think between the snails that bury themselves (i forgot we had a couple of those), and future additions like a goby and scooter blenny, maybe some more shrimp would we have enough stuff cleaning the bottom that we wouldn't need so many hermits and other crabs.

 

[jaxteller007]

To quote the guy from "True Animal Facts". That's how a hermit crab do.

Pulsing zenia?

Yes that's it. Pulsing zenia.

 

[OriginalUserName]

Yes that's it. Pulsing zenia. I told her we should wait to do coral but she was set on it, and it was pretty cheap.

I've never kept it but most consider it bulletproof. I wouldn't stress.

 

[jaxteller007]

I've never kept it but most consider it bulletproof. I wouldn't stress.

Yea it seems pretty hardy. Read that we just need to make sure to monitor it because it could spread like wild fire and take over the tank.

 

[OriginalUserName]

Yea it seems pretty hardy. Read that we just need to make sure to monitor it because it could spread like wild fire and take over the tank.

(not mine)

 

[jaxteller007]

(not mine)

That's like the one I saw when I was reading about it lol. If it starts to go crazy and we can't control it, I'll take it out and put it in the 10G tank and let it take over that. Or in the sump LOL.

 

[ThunderGoose]

I have had the best luck with the dwarf zebra hermits: https://www.liveaquaria.com/product...ge-black-hermit-crab?pcatid=613&c=497+501+613

They seem to be more mellow and less likely to go after snails in my experience but they will definitely still go after them if they find a weak snail or need a new shell.

YMMV - in my experience the dwarf blue leg hermits are the best behaved. My dwarf zebra hermit is named Dexter and now lives in the refugium. He was great fun to watch but he did massacre all the other hermits (even though there were appropriate sized shells available) and some snails.

I have emerald crabs, too, I feel them a bit of Nori about 1 - 2X / week and they're well behaved as well.

I think a lot of the problems come from stocking the CUC based on "packages." I just looked up one package and it recommends 50 hermits and 50 snails for a 55 gallon tank. My 55 has about 10 hermits and 25 or so snails at 1.5 years old. No way a new tank could support that size CUC! A better idea is to slowly add a few snails and/or crabs at a time and not put quite so many in the tank. You'll still have to clean the glass. If you don't then you probably have too many snails and some of them will start starving (which leads to hermits and others going after them...).

 

[jaxteller007]

We move all the bigger hermits over to the 10 gallon tank. Brought some new sand sifter and glass cleaning snails home. They seem to be doing well although I think one of the sand sifting ones did not survive the trip home, hasn't moved since last night with part of his body out of his shell. Same with 1 or 2 of the glass cleaning ones. We always seem to lose 1 or 2 of them as soon as they get in the tank, while the rest just solider on.

 

[jaxteller007]

We've had 2 of 3 rocket fish wind up dying and they looked just completely tore up before they died. There's one rocket that was bigger than them and seemed to pick on them to the point of them hiding in the rocks constantly. Wondering if the emerald crabs that stay in the rocks proceeded to go after them since they would stay in the rocks the entire time? Can't figure anything else out. We've moved all of the larger hermits to the 10 gallon tank and now there are only a couple small hermits in the main tank. Still have the 3 emeralds in the main tank. I worry about taking all the crabs out though. What else would we keep in there to help clean the sand, pick at algae on rocks and whatever else crabs and hermits do?