mine did this and my bigger female killed 2 of the 4 i lost recently, one explored the world of filter intakes and then she beat one up and my cuban joined in. then after i separated it it didn't make it after 2 days. its tail was like yours but it had alot of body damage also. i have noticed with bowfins once one figures out it is a badass it will never go back. i hope your will relax though.

