Chaeto with Red Nodules?

[platy]

Please see attached photo of Chaeto with red nodules?

A few weeks ago they appeared on my otherwise plain green chaeto.

Does anyone have any idea why or what they are?

Thanks.

 

[Michael Hoaster]

I can't tell. Is it pictured out of water? An in-focus close-up, in water might help. The better the pic, the better the guesses!