Daphnia pulex, popularly known as water fleas, are small crustaceans that live in freshwater such as ponds, lakes, and streams. They serve as an important source of aquatic food. Feeding live Daphnia results in a remarkable improvement in the appearance, health, and longevity of fish and other aquatic organisms. They mature in just a few days, so it does not take long to grow a stable culture.
If fish could write, Daphnia would be at the top of their grocery list. These irresistible, tasty little morsels don’t cause indigestion or constipation and are non-fattening. These little water fleas, as they are sometimes called, love to propagate, and are most enticed to do so in alkaline water (above pH 7.0) that is between 65 and 75 degrees Fahrenheit, with medium-light intensity. Incredibly, they are quite content in a relatively small volume of water as long as there is enough food and oxygen to support them.
Daphnia provides two primary vitamins that are of vital importance to fish — vitamins A and D. Vitamin A is essential for the growth and development of fish, and it also serves as an excellent anti-infective agent. Vitamin D is primarily responsible for the production of bone, and all vertebrates are therefore dependent on it. Daphnia also offers small amounts of vitamins B and C, which vary in quantity depending on what foods the Daphnia have consumed. Vitamin B supports tissue growth and stimulates the appetite. Vitamin C aids in skin formation and coloration. Finally, Daphnia provides protein, carbohydrates (sugars and starches) and fats.
There are numerous advantages to offering Daphnia in comparison to a diet consisting exclusively of dried foods. Dried foods typically lack essential vitamins. Daphnia provides the necessary vitamins in proportionally balanced quantities. As live food, Daphnia activates a fish’s instinct to hunt. Overfeeding Daphnia to aquarium fish will not pollute aquarium water because they will live until eaten later on. There are no difficult or costly requirements needed to cultivate Daphnia to adulthood.
This is a good opportunity to start your own Daphnia culture if required, or you can just feed your fish straight away. Please have a look at this page for more info about Daphnia (background, culturing, and other information).