Not sure if I have a sick angel

[DiverDown]

One of my angels has suddenly developed a wierd behavior. It won't come out while the light is on. It stays in the castle.

It looks normal, no fin rot, no fungus. It's eating, it just seems light sensitive.

Tank: 60 gal
Tankmates: 1 angel (same size, disc approx 3 inches), 1 pleco (6"), 8 skirt tetras, 3 glass cats, 1 cory, 4 serpae tetras

Nitrate: 10 ppm
Nitrite: 0
Ammonia: 0
pH: 6.9
Temp: 80

I do weekly 25 gallon water changes

 

[Zagz]

Has there been any aggression between the 2 angels? Breeding behaviour? Have the serpaes been nipping at the angels?

 

[DiverDown]

I haven't noticed any aggressive behavior, I'll have to check closer. The more I research, the more I believe it is mating behavior. No fin nipping.

 

[Zagz]

Angels when mating, chase each other, lock lips and it can seem like aggression. The female may be hiding if she isn't quite ready to mate.