I think you are right to an extent, I don't know but it may have something to do with the maturity of the animal in question. If it is not to full maturity it may not have the defense that it needs to keep other animals at bay. All coral species have a toxin defense system of some kind. Some are not noticeable to us humans and others are very toxic to us. There is not that much known on coral toxin's. There is a little research for medical science going on right now. It is a growing field. I had a neighbor that asked if he could lick one of my mushrooms (a purple one) I think I should have. He turned out to be a butt head and it would have made a good expieriment. I just don't know what I would have told the paramedics, I don't want them to take my mushrooms away.