When researchers set up the BUM to record Red Sea corals overnight, it recorded some remarkable behavior including a closeup view of corals fighting using mesenterial filaments as well as a behavior believed never before documented; the polyps of one SPS (possibly Stylophora sp.) would periodically bend towards their neighbors for an extended mouth-to-mouth "kiss."
Why do polyps "kiss" like this? We don't now yet. Researchers suspect they might be exchanging food or nutrients, which then begs the question how and why these "brainless" animals behave like this. As with many scientific discoveries, one answer begets more questions.
We can't wait to see what other secrets about corals the BUM will bring to light.