Reef Discussion

MagicJ

Moderator
Jul 11, 2011
9,650
3,761
Hobart, Tasmania
Who Removes Gall Crabs?
I recently purchased a Trachyphyllia geoffroyi and, as is quite common with these corals, it came with a hitchhiker - a Gall Crab.

I understand that these crabs don't cause any significant damage to the coral - they don't actually bore into the coral but rather settle on the coral as a juvenile and the corals grows around them.

On this occasion I decided to remove it ...

This is the tell tale sign of a gall crab - it uses its tail to block its hole
Gall-Crab-1.jpg


After its removal - the hole was about 15mm deep
Gall-Crab-2.jpg


And, the crab - they are not the nicest looking thing I have seen :)
Gall-Crab-3.jpg


It will be interesting to see how long it takes for the coral to grow over the hole.
 
E

ezza

Guest
Oh is that what they are?! I have removed some before, I had no idea what it was though.
 
Sep 24, 2013
367
280
Palm Beach
I didn't use to remove them, but changed my mind in the recent years.
I noticed an Elegance not opening so well and I started monitoring it at night, until I spotted a gal crab trying to bury in the coral's mouth.
Then I did a bit of googling and found more reports of the crabs damaging corals by burying in their mouths.

Better safe than sorry.
 

ReeferRob

Solidarité
Oct 22, 2014
2,661
931
Bel Air
The gall crabs that live in Acroporas I won't remove, but any on an LPS coral get dispatched with extreme prejudice.