I read, over and again, on the forums about how people have difficulties with clowns. They become aggressive!
Have we all been seduced by 'Finding Nemo'?
1. Clowns are the same family as damsels...aggressive fish!
2. Clowns are territorial...leading to aggression
3. Clowns mate up and lay eggs, which they defend...aggressively
My two little tomato clowns were model citizens, peaceful, attractive and interesting. one became larger, the dominant female. She became more aggressive but nothing the rest of my fish couldn't handle. Then the pair began their spawning behaviour. They adopted one corner of the tank as their base which they defended with great gusto. Resulting in a very stressed tank and fish losses. In the wild, so i have read, these fish have a territory up to 2m in diameter. This is an area roughly 3 times the area of the base of my tank!! No wonder the attacked everything, including me! The tank was just not big enough for them!
Clowns, in all their guises, are beautiful fish, which many people, including myself, introduce into totally unsuitable aquariums. We then wonder why we have problems.