What’s this on my Duncan?

[jtlmnop]

Hi,
I am fairly new to reef aquariums. My tank is 4 months old, with one fish and a few coral.

I noticed this line on my Duncan today, with what looks like some clusters of spots on the line. See photo.

It has been doing well in general, normally open and extended, but some times closes up at night.

Any thoughts?

TIA

 

[vetteguy53081]

Your pic is extremely dark blue
Please retake under white lights

 

[Rubberfrog]

It looks like a crack

 

[PeterB113]

Looks like some kind if algea maybe stuck between the 2 heads????

 

[Tcook]

Does it brush off? Is it a spaghetti worm? Looks like a small one at the base.

 

[jtlmnop]

Your pic is extremely dark blue
Please retake under white lights

I’ll try to update with a pic tomorrow, lights are out on the tank for the night.

 

[jtlmnop]

Does it brush off? Is it a spaghetti worm? Looks like a small one at the base.

I haven’t tried yet. But I just dismissed my second round of PraziPro for another reason. I would think any worms would have been taken care of, if that’s what it is.

 

[jtlmnop]

Updated pic with white light... any thought on what this could be? Is it normal?