This yolk sac is high in nutritional value. After 24 hours the yolk sac is used up and only the empty chitin shell is left. If larger Artemia are wanted, they must be fed after the first 24 hours. Harvesting Artemia nauplii is difficult for many beginners. The shells are indigestible and can even be dangerous for fry.
Older fishes spit the hard egg shell out.
To remove the crustacea, turn the air supply off. Within 3-5 minutes the egg shells rise to the surface and the nauplii congregate on the bottom. The siphoned water is discarded and replaced with aquarium water as long as the bottle still contains nauplii. As soon as the bottle is empty, we start a new culture. This way you have live Artemia available every day.