HELP.....Blue Legged Hermit Crab

[BaliReefBox]

Hi I introduced 3 blue leg hermits the other day and tonight I found 1 perched on top of a SPS orange digi and the coral appeared to be stripped in alot of places. there was another hermit at the base of the coral. the hermit was sitting on top of the digi in the circle and the arrow is the other one that has been striped. on inspection of the other digis it seems a lot have been attacked...I thought they were reef safe... can anyone help with an explanation before I toss them out cheers

 

[Reefer Matt Verified Media Partner]

I believe what you are seeing is stn or rtn, and the hermits are eating the algae growing on the dead coral skeleton. What are your water parameters?

 

[BaliReefBox]

I believe what you are seeing is stn or rtn, and the hermits are eating the algae growing on the dead coral skeleton. What are your water parameters?

no I disagree, this afternoon all corals were fine and my parameters are stable and in the zone. earlier this afternoon all the digis where bright orange all over and sprouting new growth.It was them!

 

[Acros]

I am not sure why they do it, but my blue legged hermits occasionally climb up some SPS as well.

You can remove them manually, however in my experience they do not do any harm and will come down after some time. The coral temporarily looks stressed at the site where the carb sits and will rebound in minutes once the crab gets down/blow away by current.

 

[BaliReefBox]

I am not sure why they do it, but my blue legged hermits occasionally climb up some SPS as well.

You can remove them manually, however in my experience they do not do any harm and will come down after some time. The coral temporarily looks stressed at the site where the carb sits and will rebound in minutes once the crab gets down/blow away by current.

I hope your correct. When I asked my LFS to get me some hermits they advised against them. I couldnt find any locally and had these flown in from Jakarta...maybe I should have listened to the local advice,
Lets see what tomorrow brings. If the SPS have damage and havent bounced back they will be homeless.

 

[Acros]

SPS will be fine. Observe for a week before you do anything. They are not reef safe as they have a tendency to go after snails.

In the beginning, I panicked and returned every hermit that climbed on SPS, until I stopped doing it. I will send you a pic if I catch on of them them on any coral.

 

[Mr. Mojo Rising]

I caught my blue leg hermit eating my acan coral, I sat and watched it eat a few clawfuls. I gave them all away the next day and now no more crabs in my tank ever. Crabs are always a best chance, so I dont take any chances.

 

[legionofdoon]

I've seen peppermint shrimp tear up acans and frogspawn but I've never seen my blue legs touch anything but I did have a nice colony of daisy cutters that disappeared overnight.

 

[wonroc]

Never seen a hermit red/blue touch a coral in a unloving manner

 

[BaliReefBox]

Ok well ole mate is at it again this evening but todays target is the candy cane. I inspected the digi and there is a little damage to one side but maybe its just not comfy to fully extend yet. As suggested will give it awhile and see how things progress as I like the idea of them cleaning up. I have read previously that they may go snails due to shell envy and to try and prevent this I have scattered 6 or 7 largish very stylish empty shells arounf in case they feel the need of a new home...
Cheers and thx for the advice people

 

[Acros]

@BaliReefBox Here is one of my blue legged hermits on a digitata. I don’t really do anything about it, they get off/are blow off by current after some time.

 

[Dkmoo]

I've had hundreds of hermits with legs of all the colors of the rainbow. None had ever "ate" any corals (sps or lps). IMO it falls in the below 3 categories when people think its eating corals.

1) they are eating corals that are already dead or mini algae sprouts (their favorite) thats growing on the receding tissues

2) they are picking at the tiny morsels of food that the coral polyps are catching. This is especially frequent when you are feeding corals. When they do this their pincers are very precise. Coral may temporarily retract but they are not hurt

3) only time when I can possibly see them going after corals is when they are starving and have no other source of food. This has never happened in my tank so im just theorizing.

My .50

 

[Acros]

Sunday, blue legged hermit chilling on my digitata:

Monday, coral looks irritated locally:

Tuesday, can’t find a trace, coral looking back to normal:

 

[BaliReefBox]

Sunday, blue legged hermit chilling on my digitata:

Monday, coral looks irritated locally:

Tuesday, can’t find a trace, coral looking back to normal:

Yeah thx for that. After my initial panick I kinda assumed things would go back to normal as so many here recommend them as cuc. Yesterday I found one in amongst the candy cane, he was there for hours and I think he was pretty much stuck. I got a pair of tweezers and got him out but it was an effort thats for sure.

 

[BaliReefBox]

edit

 

[Gatorpa]

Never seen a blue leg eat a coral itself.
As others have noted they pick at all kinds of stuff in and around the corals….. that’s part of the reason they are there.

In fact I see them start picking at algae when it’s almost not visible to my eyes…

Now I never got blue legs from Jakarta either…

 

[mckinney0171]

Hermits climb on my corals to remove detritus and nuisance algae. They don’t ever harm my corals.

 

[snorklr]

i think the blue leg hermits that most of us have in the US are sourced from the Caribbean...maybe you're dealing with a different variety whose habits are more agressive?