Just after sunset, about every other week for the past six months (often on weekends!!), two angel fish perform part of their mating ritual.
The female angel fish started laying eggs suddenly a year after she joined the aquarium in 2007. She was the remaining survivor angel fish from an original group of four babies. Two additional angel fish, a male and female (now, I know for sure) joined the tank about a year ago.
Eventually, infighting between the three of them made it impossible to keep together as they grew larger. One day, they started violently fighting. Two females against each other. The male turned on the weaker female. The two female fish were separated (see above left for the newer female and the shadow of the original female on the right of the the blue tank divider). The eggs from the original female are visible as white dots to the right of the blue divider.
The video shows the female "fanning" the eggs which are stuck to the side of the plastic divider.
Each time, she spends all of the time fanning them and offensively protecting them from other other fish in the tank. The male angelfish (who was moved to the side of the egg laying female) also protected the eggs from the community fish. They would spend hours starring and guarding the nest.
But, time after time- over a dozen egg laying events- the eggs were gobbled up by the angel fish.
They seemed to lack the understanding what to do after a while of protecting them. They got hungry, pecked at some of the eggs and liked the taste of roe (fish eggs).
Recent note: While I was gone one day, a community brawl ensued. In September 2008, the egg laying female and male somehow switched sides with the separated female.
The two sword fish also got into a fierce fight with bruises, but kept to their sides (also separated with the divider). Two weeks later, the egg laying female suddenly died. The male was moved back with the separated female, after a brief violent encounter, they made up, paired up and the new female layed her first time at the end of September. The male angel fish is obviously happy.