Disease Indentification

[dale_d_h]

i have a zebra danio with a large red growth coming out of its right gill. what is this?

 

[WILDER]

How many gallons or litres is the tank.
How many fish and which type.
Water stats in ammonia, nitrite, nitrate, and ph.
Are the gills red and inflamed.
Can you describe the growth in more detail is it smooth looking.