OK I have renovated my 180 gallon, corals throughout the tank have been thriving and growing. I have a purple/blue acro near the top of the tank about 12" from water line maybe a bit more. It seemed to be fine for about 6 months but is now showing some white blotches on the back side of the coral near the tops. For some reason you don't really see it fron the front, I only see it when I go into the fishroom and look through the back. The front has all polyps out all the time and colour is great. This coral has a crab inside so I was thinking maybe he is eating it. The white does not look like a gradual fade of colour, its just seems like flesh missing and there is white spots. Anyone know what could cause this?
SPS coral getting White blotches
- Thread starter Chago09
- Start date
ummm light I doubt is the problem but flow might be. It has some rock formations behind it but a couple inches away. There is a crab in there though and I wonder if he is the problem. I always see him picking away away eating something off of the coral. Its so small though I can't tell if its eating something off the coral or the actual coral itself
welldigger
New member
What do you have for fish? I have a color blenny that chomps on sps and leaves blotches.
welldigger
New member
Bi-color blenny. sorry, damn Android.
welldigger
New member
I found this;
Chances are that the crab you have found will not be a problem. Crabs found in heads of SPS corals are usually of the Family Xanthidae. They are typically commensals which sometimes protect the coral from predatory fish or invertebrates. However, all of these crabs should be watched carefully as not all of the Xanthids are harmless - see below. Trapezia sp. (Family Trapeziidae) is usually found in Pocilloporadae while species such as Tetralia and Domecia (Family Xanthidae) are the typical residents of Acroporidae.(Delbeek and Sprung The Reef Aquarium, Vol. II, pg. 324). In the experience of the author and other reefkeepers that the author has conversed with, hairy brown crabs imported in SPS colonies tend to be harmful rather than commensal, while the tan, smooth shelled crabs like the one in the above picture are peaceful, well-behaved residents.
Chances are that the crab you have found will not be a problem. Crabs found in heads of SPS corals are usually of the Family Xanthidae. They are typically commensals which sometimes protect the coral from predatory fish or invertebrates. However, all of these crabs should be watched carefully as not all of the Xanthids are harmless - see below. Trapezia sp. (Family Trapeziidae) is usually found in Pocilloporadae while species such as Tetralia and Domecia (Family Xanthidae) are the typical residents of Acroporidae.(Delbeek and Sprung The Reef Aquarium, Vol. II, pg. 324). In the experience of the author and other reefkeepers that the author has conversed with, hairy brown crabs imported in SPS colonies tend to be harmful rather than commensal, while the tan, smooth shelled crabs like the one in the above picture are peaceful, well-behaved residents.
