My blue gorami was picked on a lot. Up to the point she hid away and died. She died of swim bladder infection, was it my water or possibly damage to her swim bladder when she was being picked at.
Ok. The pink nose was the bullyer male, the her fish was healthy until he picked on her to death. She was the one with swim bladder disease, the male had the pink ( i think it was just coloration). So what caused her to die?
Stress. If he been pecking her in the stomach area he could of damaged the swim bladder. Ir she was already ill.
Always separate fish if there being bullied. Rehome one of the fish.
Can you post your water stats please in ammonia, nitrite, nitrate, and ph.
When a fish is stressed it will weaken the fish immune system.
If a fish is being bullied it's best to isolate the bully.
Swim bladder can be caused by -
Bad water quality.
Unstable diet.
Constipation,
To many dried foods.
Injury.
Birth defect of the swim bladder.
Bacterial infection of the swim bladder.
Internal parasites.
Unstable temp.
Deformed swim bladder.
A link to swim bladder for you.
http/www.flippersandfins.net/SwimbladderDisease.htm