From observations in an aquarium, the spawning of butterfly fish occurs between multiple males and one female in the early hours of the night in March, August, September and October. No real for-sure answer on the ages..... But this is only from tank studies.
The answer is spawn
fish that can spawn up to 100,000 eggs each spawn
Salmon is one fish that travels up a river to spawn.
lined butterfly fish get eaten by by crab fish.
Angelfish are quite closely related to butterfly fish.
spawn
Butterfly Fish eat tiny shrimp, worms, and algae.
Butterfly fish are from all over the world and live in the coral reefs.
There are many species of "Tropical Coral Reef Fish" that are commonly called "Butterfly Fish"
It depends what kind of "butterfly fish" you are talking about. There are fish like Butterfly Koi and such that eat different things. They will probably eat what most any other fish eats, Bloodworms, fish flakes, or fish pellets.
Predator fish that eat butterfly fish include snappers, sharks, eels and other larger predators. Butterfly fish are small, growing to up to 6 inches in length.
Butterfly fish belong to a family called Chaetodontidae. They are also invertebrates.