Raising Daphnia (Part 1)

A few weeks ago, I purchased a Daphnia culture. It was just a pop bottle with green water and a bunch of tiny swimming critters called Daphnia.

Wikipedia starts by saying: "Daphnia are small, mostly planktonic, crustaceans, between 0.2 and 5 mm in length. Daphnia are members of the order Cladocera, and are one of the several small aquatic crustaceans commonly called water fleas because of their saltatory swimming style (although fleas are insects and thus only very distantly related). They live in various aquatic environments ranging from acidic swamps to freshwater lakes, ponds, streams and rivers."

(Photo on left is a female Daphnia. The photo is by John P. Clare. Visit his site's section on Daphnia for ample information on this creature.)

I poured out the Daphnia culture into two different receptacles: A small one gallon aquarium and a one gallon plastic jug. In the aquarium, I added RO water and fed the Daphnia using Zoe and a powdered milk solution. After a week, almost all Daphnia in this receptacle were dead. In the jug, I added green water from another aquarium. These stayed alive and continued to swim around for days.

When I came back from vacation Saturday, I noticed Daphnia were no longer swimming in the gallon jug either. It seems both cultures died out. There were a few, very small creatures still present in the small aquarium.

I poured out both cultures into my now empty 10 gallon aquarium and added 4 gallons of very green water collected from a water change. I have an abundance of green water coming from my new 20 gallon setup. Other than this, I am not too sure how to feed or grow these insects. The goal is to grow enough to feed fish.

The Daphnia culture is now sitting on the basement floor near the washer and dryer. I setup a light fixture on it and poured in extra water lettuce plants. I'll check up on it in a few days to see if Daphnia are still present.

I will be reading John P. Clare's Daphnia: An Aquarist's Guide more attentively in the coming days as it should provide the information I need to successfully increase my Daphnia culture.