Goliad Farms, LP - Daphnia magnum

Goliad Farms, LP

8497 FM 622
Goliad, Texas 77963

Voice 361.645.2252
Fax 361.645.2258
Email goliadfish@goliadfarms.com

Contents

Foods

Live Foods

Daphnia magna

Daphnia magna is one of the largest of a vast array of tiny aquatic crustaceans often called "water fleas" for their hopping motion as they swim. It is an easy to culture live food that is an excellent size for many juvenile and adult tropical fish.

Size: This crustacean reaches about 4mm (1/8 in.).

Description: This minute crustacean lives on algae and other microorganisms. It is clear to green or even red depending upon its diet and water conditions.

Environment: This species survives happily in aquarium quality water. It can tolerate temperatures as low as 0C (32F) and high as 35C (94F) but prefers temperatures ranging from 20-25C (68-76F). pH is not important. Culture containers (the author prefers 32 gallon plastic trash cans, preferably yellow or white colored) should be aerated and provided a good food source, such as algae or yeast.

Geographic Range: Worldwide in temporary body of water.

Uses: This live food species is an excellent live food for most juvenile and adult tropical fish. It has the advantage of surviving aquarium conditions indefinitely so that it can be fed in abundance without fear of water fouling (do not, however, feed too many without adequate aeration since this organism will compete with fish for oxygen). Fish are attracted to the hopping motion Daphnia makes as it swims. This live food is beneficial in tanks of Betta fry since the fry can eat the live-born Daphnia offspring while the adult Daphnia help filter the water by eating microorganisms encouraged by the heavy feeding necessary for fry survival and growth.

Culture: Culture of Daphnia is simple in aquaria and other containers such as plastic barrels or trashcans. Culture instructions follow:

1) Fill a container with aquarium water and place it in a sunlit location where the temperature can be maintained between 15-25°C (about 60-80°F). Add a number of pond, mystery or apple snails.
2) Aerate the water gently with an open airline tube or coarse bubbling airstone (small bubbles can be damaging to the Daphnia).
3) Feed the snails lightly with flake foods or greens such as lettuce or cabbage.
4) When the water has turned green, add a starter culture of Daphnia. A few dozen will be enough.
5) Continue to lightly feed the snails. Within two weeks there will be enough Daphnia to harvest.
6) Harvest by netting with a fish net. Up to 25% of the organisms can usually be harvested daily.
7) Feed by dipping the Daphnia into the aquarium. Do not feed massive amounts without adequate aeration, since Daphnia can compete with the fish for oxygen.
8) Cultures can also be fed by adding green water or even small amounts of activated yeast to the extent that the water is maintained slightly turbid.
9) Cultures should be sub-cultured when production declines although siphoning the bottom of the container and replacing part of the water can rejuvenate a flagging culture. It is wise to maintain replicate cultures in case a culture crashes suddenly. Whenever the Daphnia begin to produce black egg cases at their posteriors, it is time to subculture. They only produce these "resting" eggs when stressed in some fashion.

Additional Information and Photos and Sources: For more information on this species, photos and proven sources, which we recommend, for this live food, click on one of the following links:
http://www.lfscultures.com/p13.html