Growth or recession ?

[Gustozzzo]

What is that white film growing on the edges of this favia ? Looks like spider webbing .

 

[EnterName]

Have you tried blowing the film off with a feeding pipette? It's possible that it's just some mucus produced by the coral to hold onto some food it tried to catch. In a worst-case scenario it's the beginning of a bleaching process, but then you should be able to see a bit of skeleton. If you search for "Favia skeleton" online you will see their typical skeleton pattern, which might be what you mean with spider webbing, but let's hope that's not what you meant

The image is very blurry so I can't really see what it is.

 

[Gustozzzo]

 

[EnterName]

I assume the bright stuff can't be blown off with a pipette and we are looking at bleached coral tissue or even skeleton shining through?

In that case the coral might be doomed. It has too much/little flow/light, isn't happy with the water parameters, or has some infection that would require appropriate treatment, I suppose

If however it's just some mucus it uses to keep food in place, its fine. Under blue light it becomes even more difficult to differentiate.