Ok I had a nice sunny d that looked like it was doing well and woke up this morning and the plug that he was on well he's not there anymore I mean it looks like a crime scene the plug has a little algea on it and where the sunny d was it's completely clean the only thing new we have done to the tank is add 2 black seahorse's I also have a black sea urchin but never had him bother any thing had him go over my space monster plug and everything was fine just had a cleaner plug do you think the seahorse could have did anything?