lyretail not aggressive....squareback more aggressive...1 male 1 female for my lyretail...lyretail very easy to keep..dun worry about the male to female ratio...if u want to know..its 1:4...
squareback female is yellow in colour...very easy to keep..but once they become larger...they will be more aggressive to other anthias and its own kind...
most impt is, have to feed at least twice a day, preferably with mysis and brinshrimp mix tog...pellets not good for them...tho they will take coz they will get diahorrea easily and die...
and must have hiding place for them to sleep coz each anthias will reserve their own place n they will sleep in that same place forever...unless u introduce new fishes that chase away their former place...