Daphnia Starter Culture

Daphnia magna are freshwater crustaceans colloquially known as water fleas that have been used by aquarists as live food for well over a century. Their value extends beyond mere nutrition: Daphnia contain the digestive enzyme chitinase and act as a mild laxative in fish, helping to clear internal blockages caused by dry food and promoting digestive health. They are also an excellent conditioning food that stimulates spawning behaviour in many species.

This starter culture contains live adult and juvenile Daphnia magna in 250ml of green water, sufficient to seed a 5–20 litre culture vessel. The colony reproduces rapidly under good conditions, cycling from start to harvestable population in 7–14 days. Harvested Daphnia are fed to fish live, providing a moving target that stimulates natural hunting behaviour and promotes activity in well-conditioned breeding fish.