Dead Skinless Neon

[diet]

Just found a skinless still living (barely) Neon Tetra its tail fin was missing and as u can imagine it was very weak so i took it out of the tank an humanly put it down,

Any ideas on what could of been the cause??

All water tests are normal and all the other fish are normal,

The only new addition to the tank was 2 blue goruami's around a week ago

 

[WILDER]

Poor thing, any of the neons lost there vibrant red stripe, does the stripe looked bleached out.
R.I.P.

 

[diet]

all the neons look as bright as can be only noticed the poor thing when i checked the internal filter as my male swordtail has a habbit of getting in there and swimming around at the top of it.

The neon was stuck bum first in the intake try to swim i have no idea it was so i pushed him back out into the tank and noticed he was completly red,

any ideas??

 

[WILDER]

Ok, the filter damaged him then, maybe want to think of cutting a peice of net up and putting it on the out take tube with a rubber band, so it dosn't happen again.
Block the hole up with some filter floss if its a juwel box stop the fish getting in there.