Elegance coral not opening up ! burrowing Crustacean.

[Brad Wilkins]

Hi, i bought a bunch of Elegance coral about a month ago and the best one by far was a yellow but it only barely opened up. Just the other day it was looking a little sick so i had a closer look, specifically at what i thought were three off shoots that never grew. They were like round holes but when i looked closer, i noticed what looked like a cap that had moved revealing a leg. After pulling the Elegance out and digging the hole with my tweezers i pulled a Crustacean of some sort. Can anyone please ID

 

[ISpeakForTheSeas]

Hi, i bought a bunch of Elegance coral about a month ago and the best one by far was a yellow but it only barely opened up. Just the other day it was looking a little sick so i had a closer look, specifically at what i thought were three off shoots that never grew. They were like round holes but when i looked closer, i noticed what looked like a cap that had moved revealing a leg. After pulling the Elegance out and digging the hole with my tweezers i pulled a Crustacean of some sort. Can anyone please ID

That's the ventral side (the underside/stomach) of a female gall crab (taxonomic family Cryptochiridae); she doesn't seem to be ovigerous (so no eggs that I can see) - if you can get pics of the dorsal side (the topside/back of the crab), then I may be able to ID it.

It has an obligate relationship with the coral - so I doubt the crab would survive long without it.

That said, gall crabs are considered parasites; they shouldn't kill a coral, but they burrow into the skeletons - so if it's a big crab and a small coral, it's a bad combination. If the coral is a decent size, then the crab should just cause a mild deformity; problems generally only arise from algae that grows on the deformed coral skeleton that sticks out through the dead skin.

So, basically, if the coral is big, it'll be fine; if the coral is small, it could die; if the coral is medium-sized, it'll probably be unhappy, but it should survive just fine.

 

[Brad Wilkins]

That's the ventral side (the underside/stomach) of a female gall crab (taxonomic family Cryptochiridae); she doesn't seem to be ovigerous (so no eggs that I can see) - if you can get pics of the dorsal side (the topside/back of the crab), then I may be able to ID it.

Thanks for the ID. Unfortunately i cant take another photo as I flushed them after taking the pic's. Hopefully i should see some growth now the irritants are gone. Cheers.