My danios think they are bettas

[Opcn]

I've got three male danios together (its a school of 4 with the female glofish) and just now they are fighting they have flared out all there fins and there operculum and scales are falling like snow (well I've seen 3 fall sofar) It used to be a school of 7 but 1 long finned fem got eaten my the filter 1 albino juvie went the same way and one small male went jimmy hoffa on me. shoul I got to the LFS and buy 2 more to take the agression?

Opcn

 

[Loveless]

I think you should check that filter first? it shouldn't have killed any of your fish, isn't there some kind of fish/debris guard on the intake tube?

I think daninos will only do well in a group of 6 or more