Whats on my Duncan?

[fernalfer]

Ok i have a Duncan that gets these little things every now and then on it. almost looks yellow, they don't seem to move and also do not irritate the coral. It stays open wide. It also is not hurting the coral healthwise because it is my fasting growing coral sprouting 5 new heads in the last 3 weeks.

anyone have a clue what this is?

 

[Va_Reef]

Just looks like waste to me, from the duncan.