Identifying growth on my lobo coral

[Auric]

I've got a RSM130 with three Ecoxotic Pro Modules - two 12k white and one 445nm blue, plus another 445nm blue. My Aussie Lobo's been thriving in the sand bed, munching on Mysis shrimp for 7 months now, no issues whatsoever. Last night, with just the blues on, I took a peek and noticed what looked like a tear from its mouth to the outer ring, accompanied by white, stringy, balled-up strands - kinda like a ball of intestines. Nothing new has been introduced to the tank in weeks. I'm running a Proflex Model 1 refugium/sump instead of the built-in one, and it's got a growing ball of Cheato. I've attached two pics - one from last night and one from the day before. Could my Lobo be too close to the frogspawn? I've never seen any sweeper tentacles coming from it. Would appreciate any insight.

[rusticore]

Those mesenterial filaments are essentially a ball of intestines, and it appears your coral is feeling threatened or defensive. I agree that the proximity to the frogspawn is likely the issue. I would recommend relocating it at least 8 inches away to give both corals some breathing room. Once you've moved the Lobo, which I think might actually be a Trachyphyllia - it's a bit hard to tell with all the puffiness, you can consider shifting the frogspawn a bit to the left; in my opinion, it's a tad too close to that Duncan.

[Auric]

Thanks for the advice, I'll definitely move it further away from the frogspawn. You're probably right about the ID, I was told it was an Aussie Rainbow Lobo when I bought it, but I'm still learning and it's possible it's actually a Trachyphyllia - I'll have to do some more research.