Identifying growth on hammer coral

[Nexario]

I've got a weird issue with my coral - there's this bubbly growth right below the fleshy part, basically on top of the stem. It's completely covering the area. I've tried searching online, but nothing seems to match what I'm seeing. Has anyone here ever dealt with something like this?

My parameters are:
Ca 400
Mag 1180
Alk 7.8
Nitrate 0
Phos 0
Salinity 1.025

My tank is about 6 months old.

[zenoxa]

I'm thinking it could be a reproductive thing. I came across this article from Advanced Aquarist that might be helpful - it talks about coral reproduction and has some images that resemble what you're describing.

[fleeton]

I think it's a sign of stress. My parameters are similar and I had something similar happen last month. I'm not saying that's what's happening with yours, but it's worth looking into. Have you checked for any pests or changes in water quality?

[zenoxa]

I'd say they're similar, but not identical. I've come across an article that might help clarify the differences. http://www.advancedaquarist.com/2012/10/corals

[lumber6]

That's a great sign, the head's preparing to split. Mine does this from time to time, and I recall one instance where I had a massive bubble covering the entire area.

[Auric12]

It's definitely a frogspawn, and while they're similar to hammers being from the same genus, they're distinct species. Looks like it's gearing up to split soon.