Yep, that looks like a Zoo eating Naudi. I battled them for almost two months in my BioCube. I would wait till lights out and check the tank with a flashlight and use an eye dropper to suck out the adults. I also did weekly dips of all my frags and removed quite a few egg clusters. Look for small white, round (almost donut like) clusters in a clear mucus. The eggs and mucus can be hard to remove, I had to use tweezers to get the eggs off.