i cant tell with my firemouth yet. he was sort of tough in the beginning, but the he dissapeared for a weak, i never say him at all. but now he is comming out again, acting like the fish i bought.
i have been watching the jewel fish, and yes he is somewhat aggressive. he usually chases the headstander, but for good reason. the headstander tries to sneak up on it and bite its fins, but the jewel turns and chases him around a few times. suprisingly, he doesnt mess with the smaller krib at all. the jewel and the firemouth sometimes get in a staring contest but that is all. the rest fo the fish the jewel leaves alone, probably because they are twice its size. i will be watching him closely...
ill keep you updated, unless i get kick out or something (wouldnt be the first time...)