Can fish feel sad?

Our Angelfish last week laid eggs on the bubbler in our aquarium. The other Anglefish, a small silver one, fertilized the eggs. All afternoon they watched over them, attacking any of the smaller fish that would come near. The lights went out, which is the cue for the giant pleco to come out. In a flash, he sucked up all the eggs.

The next day, our large black Angelfish didn’t really eat, kept to herself, mostly in the corner of the tank. no more racing and chasing.

I can only think she felt sad, disappointed in her fish mates.