Everyone is naming the nasiest cichlid based on narrow personal experience. It won't be a fair comparison unless one has the chance to house them together in the same tank, sort like putting them in a boxing ring.
I have always kept mixed CA/SA, Tanganyikans, Malawian and Victorian cichlid tanks and can attest from personal experience that as a group, African mouthbrooders are more nasty than CA/SA pound for pound. It doesn't matter that Dovii or Midas can turn into a monster when they get big, but at 6 inch, they are whimp in a box ring match with mouthbrooders. Each time when I introduce new juvenile CA/SA to my mixed tank, I have to watch out the smaller mouthbrooders as they will immediately pick on the newcommers, while the large CA/SA ignore them. Eventually, the CA/SA will outgrow the mouthbrooders, but it's comical to watch the diminutive mouthbrooders continue challenge the CA/SA at twice their size. Once for while, my giant CA/SA still got split fins from guerrilla attack from the diminutive mouthbrooders but there is nothing they can do about it as the Africans are smaller, quicker and can hide.
Egg laying Tanganyikans and CA/SA only become aggresive when they are reaching sexual maturity or attempting to breed, and some will mellow down when they get old. Mouthbrooders are aggressive at all time, when they are young, mature or old. Egg layers claim a fixed nesting territory with aggression during breeding, and don't pursue fish outside their boundary. Mouthbrooders have no fixed nest and their personal territorial space move througout the entire tank, so their victims have no place to retreat but have to run constantly from their moving bullies.
I have always kept mixed CA/SA, Tanganyikans, Malawian and Victorian cichlid tanks and can attest from personal experience that as a group, African mouthbrooders are more nasty than CA/SA pound for pound. It doesn't matter that Dovii or Midas can turn into a monster when they get big, but at 6 inch, they are whimp in a box ring match with mouthbrooders. Each time when I introduce new juvenile CA/SA to my mixed tank, I have to watch out the smaller mouthbrooders as they will immediately pick on the newcommers, while the large CA/SA ignore them. Eventually, the CA/SA will outgrow the mouthbrooders, but it's comical to watch the diminutive mouthbrooders continue challenge the CA/SA at twice their size. Once for while, my giant CA/SA still got split fins from guerrilla attack from the diminutive mouthbrooders but there is nothing they can do about it as the Africans are smaller, quicker and can hide.
Egg laying Tanganyikans and CA/SA only become aggresive when they are reaching sexual maturity or attempting to breed, and some will mellow down when they get old. Mouthbrooders are aggressive at all time, when they are young, mature or old. Egg layers claim a fixed nesting territory with aggression during breeding, and don't pursue fish outside their boundary. Mouthbrooders have no fixed nest and their personal territorial space move througout the entire tank, so their victims have no place to retreat but have to run constantly from their moving bullies.
