Help Glowlight danio with chunk missing from side. What to do

Hi there,
New here and was wondering if anyone can help me.
I have just noticed my male glowlight danio has a chunk missing from its side and seems bad. see photo. I add the glowlight danios to my community Tank about two months ago. I noticed right away that they like chasing each other. The females pick on the male a little. The male also looks a little bit deformed. I could be wrong. I’m not sure what’s happened but I don’t have a hospital tank set up so I can’t seperate and not sure what I should do next. Any help will be appreciated.

34 gallon tank (130L) Lightly planted

(In the tank)
1 male apistogramma agassizii
2 female bristlenose pleco
3 CPD danio (2 female 1male)
4 glowlight danio (3 female 1)
1 male panda Cory
2 male zebra Cory

Temp 26c / 78.8f
PH - 7.5 (I would like it to be 7 but seems to keep stable at 7.5 so leaving it alone)
NH4 - 0
NO2 - <0.01
NO3 - 5

This is one of those situations that you have to be really careful about what you purchase. Be really careful to only take home the fish you want. Select your fish and make sure those are the fish you get. Do your research and make sure that the fish you get are healthy. These glow light danios don't look great. Sorry!