Ever hear of coral eating Hermits?

[tkmak]

I have been having a bit of a problem with my corals. both my red and green flowerpots, my yellow leather, pipe organ, and kenya tree have all been showing signs of being nipped/eaten. Therefore they have all been closed up for the past 2 weeks or so. I thought it a water quality issue, did a few water changes, checked my levels. all ok there. (1.025, 80.2degrees, 0nitrate/nitrite/ammonia), calcium and dKH all at the upper levels, ph 8.11. Thought it might be some unknown chemical, placed carbon in the filter, etc.

granted I haven't looked during the night, but during the day the blue legged hermits are all over the corals, esp the ones that have had probs.

Other inhabitants? PB Tang, firefish, lawnmower blenny, McCoskers and 6 line wrasses, 3 sally lightfoots, about 40 blue legged hermits, 2 peppermints, 3 emerald green crabs.

I just started to pick them out and put them in the refug, but anybody got any other guesses?

 

[treehugger]

I've definately seen them swarm corals that are super stressed/dying. I had some that would eat the dying flesh around frags of acans that I had but never went as far as nipping at healthy pieces. I have heard of some PB tangs "grazing" as well. Good look

 

[Chichas01]

My guess is it could be the emerald crabs. Remove them and see if things improve.
I thought about getting one but decided against it after seeing lots of articles like the ones here:

http://www.reefland.com/forum/reef-aquariums/435-emerald-crab-eating-my-candy-cane-coral.html

http://www.aquariumadvice.com/forums/f11/emerald-crab-eating-zoas-91726.html

http://www.aquariumadvice.com/forums/f33/emerald-crab-eating-my-starfish-47412.html

http://www.thereeftank.com/forums/f6/emerald-crab-eating-mushroom-73818.html

 

[NaH2O]

What size tank? Unless you have a huge tank, your tank seems to have a rather large crab population. I'm not a fan of overstocking crabs of any species.

I, like Chicas01, wondered about the emerald crabs.

As treehugger stated, its possible the hermits are eating away tissue that is dying. The other possibility is there is another predator in the tank eating in the night, and your hermits are picking up the tissue bits that were left behind and dying.

In the meantime, I would remove as many as you can, including the sallys and emeralds (if you have a place to put them temporarily), and watch your corals for signs of improvement. Otherwise, you may have to get on your night vision gear

 

[luke33]

I bet the crabs are eating the dead flesh. You may have a eunicid bristle worm eating the corals or something like that. Definately worth a flashlight look at night. I'd really keep a close eye on the corals getting picked on.