Crab snapping branches on SPS?

[crazyfishmom]

Has anyone heard of this? I have been waking up to find branches completely missing off of SPS frags or colonies. Any thoughts? I think it must be a crab but no idea whether this is common or whether I should just start pulling all crabs out of the tank. Any thoughts?

 

[ZaneTer]

I have only had this happen when my fish get spooked at night and slam into the branches.

 

[feelingfishy]

Yes, my largest male emerald crab took chunks off my small JF Homewrecker frag. There are no other culprits as all I have is 6 fish, Mandarian Dragonet, Bicolor Foxface, pair of Mocha Gladiator clownfish, Midas blenny, and a Royal Gramma. None of which have ever shown any aggression towards any coral. Now the inverts I have are 8 Emerald crabs, 60+ Blue Leg hermits, 100 Astrea snails, 10 large Ceriths, and 100+ Dwarf Ceriths. The aquarium is a 2100 CADE so 235 gallons.

I used to have Dino’s ( which resolved quickly after bringing nutrients from 0/0 to 7/.03 ), and plenty of algae for all the inverts to eat, but as my tank has matured there is hardly any left except in the sump. This I think was the cause of the rouge crab which I have confined to the refugium. Since this incident I feed plenty of sinking pellets as the lights go off to keep the inverts fed and I have had no others issues.

The frag is starting to recover so ye I’m not too sad about it.

Attached are pictures of just before and immediately after.

 

[crazyfishmom]

Yes, my largest male emerald crab took chunks off my small JF Homewrecker frag. There are no other culprits as all I have is 6 fish, Mandarian Dragonet, Bicolor Foxface, pair of Mocha Gladiator clownfish, Midas blenny, and a Royal Gramma. None of which have ever shown any aggression towards any coral. Now the inverts I have are 8 Emerald crabs, 60+ Blue Leg hermits, 100 Astrea snails, 10 large Ceriths, and 100+ Dwarf Ceriths. The aquarium is a 2100 CADE so 235 gallons.

I used to have Dino’s ( which resolved quickly after bringing nutrients from 0/0 to 7/.03 ), and plenty of algae for all the inverts to eat, but as my tank has matured there is hardly any left except in the sump. This I think was the cause of the rouge crab which I have confined to the refugium. Since this incident I feed plenty of sinking pellets as the lights go off to keep the inverts fed and I have had no others issues.

The frag is starting to recover so ye I’m not too sad about it.

Attached are pictures of just before and immediately after.

Thanks for the tip. I might start trying to do that. It’s been several pieces now that he’s taken a limb off.