For sure. I do have a FOWLR. I had a couple our nudibranchs about 6 months ago, but thought they were eaten by my puffer as I have not seen them in 5 months. I do have a large sea hare, could it have laid eggs unfertilized? and of course many snails... I have seen this on 2 or three different LR areas.Not necessarily! A big percentage of nudibranchs are coral predators. If it's a FOWLR...no problem.