Split/torn Fins

[Dunkal]

Hi, I have a pair of Kribs and 6 cherry barbs and Krib fry(2 days old). I have noticed he cherry barbs fins and tails ripped and torn. It must be the Kribs nipping at them, defending their fry.
Today I noticed the end of the female Krib missing. What disease can this be?? Does it spread?Is it finrot?
Please help as I dont know what to do

Thanks

 

[WILDER]

Need to seperate the fin nippers so the fish fins can heal.