I know this does not belong in this section but I hava a yellow tang and a powder brown amongst many different types .Well my bro traded me a yellow tang for some galaxia,because his tang was to agressive towards his other tankmates.Now he gets chased from one side of my 220gal to the other by the other yellow one and sometimes the powder brown one .Now is that because same tang species are supposed to be kept in pairs of 3 or more.Thanx.