dunno if this has happened to any of you, but when schlemm was nearing the end our brittlestar (green) attacked him and managed to mangle an arm before my distraught mother wrestled them apart. i believe it may have been possible that schlemm wouldve lived a bit longer if this incident hadnt occured, since it made him severely stressed out for about 24hrs before he calmed down and then passed. so although the star was a great help in tank cleanliness when schlemm was healthy, i think it would be wise to remove such animals when ur octo is nearing the end. just a thought. it was quite tragic for my mom, dont want anyone else to have to deal with it.