Live Daphnia Magna

Daphnia magna is a large species of freshwater “water flea” widely used in aquaculture, aquarium feeding, and scientific research. Though not suitable for saltwater reef systems, it is an outstanding live food option for freshwater fish and fry.

Why Use Daphnia magna?

1. Ideal Size & Movement
Its jerky, pulsing swimming pattern strongly triggers feeding responses in fish. Because D. magna is relatively large compared to other Daphnia species, it is especially well suited for medium-sized freshwater fish.

2. Excellent Digestibility
Daphnia have a soft body and natural fiber content from their chitinous carapace, which can aid digestion and help reduce bloating or constipation in fish.

3. Natural Water Clarifiers
As filter feeders, they consume suspended algae and bacteria. In culture systems, they can actually help maintain cleaner water conditions.

Nutritional Profile

• Moderate protein content

• Low fat compared to brine shrimp

• Nutritional value depends heavily on what they are fed

Like brine shrimp, Daphnia magna can be enriched by feeding them high-quality microalgae, spirulina, or commercial enrichment diets before offering them to fish. Their gut content significantly influences their overall nutritional value.

Best Uses

• Conditioning breeding fish

• Feeding fry and juveniles

• Stimulating appetite in picky freshwater species

• Providing a safe live food with low fat content

Important Note for Reef Keepers

Because Daphnia magna is a strictly freshwater species, it will not survive in marine or reef aquariums. However, it can occasionally be offered as a temporary treat to marine fish if rinsed, though it should not be relied upon as a primary food source in saltwater systems.