my little Cuban LOVES to fight. they are troublemakers and behave almost as though they have something to prove. my little Cuban is 4 inches and doesn't want anything in his space. he is EXTREMELY active. ive never had a fish that fast and active,its great really. I bought a 4 inch dovii I wanted to put in my 125 but decided to see how he got along with my Cuban in my 20 gal growout and they immediately went at it. he knew he was no match physically but he would take his losses,hide in the plants and dart and attack the dovii any chance he got. he just kept comin for more. I knew he was gonna be an awesome fish before I bought him. his siblings and him wer fighting tenaciously over food in the tank I bought him from. yesterday he was swimming rapidly in front of the glass trying to get my attention ther was a fly that landed on the front of the glass he was trying to eat it and it started flying around and he was chasing it. hes the coolest fish I have and I have a jag,dempsey,mayan,firemouth,convict,geo and dovii. love that little bastard.