by Peter Brown

I breed Nothobranchius species and like to add Paramecia to the cool hatching water that I use. These single celled aquatic microorganisms not only provide a useful additional food source for the first days of life but also seem to help/encourage the hatching process. Paramecia are just visible to the naked eye. If held up to a bright light they can be seen swimming in ‘clouds’ in their culture jars. As with all live fry foods there are many ways to culture them. For Paramecia I like to use hay. I boil a good handful of hay up in an old electric kettle using rainwater. This is allowed to cool and re-oxygenate for a couple of days. The amber coloured liquid is then poured into a jar and a small amount of the boiled hay is cut up and added along with the starter culture. The jar should be covered to reduce evaporation. If kept at 20-30F the water will  initially go cloudy, but in a few days  will clear, and clouds of Paramecia will be visible. I find that the culture can easily be kept going for many weeks using rabbit food pellets as food. I just add 1-2 pellets every 2-3 days or whenever the pellets sink and break down. To feed Paramecia to the fry I use a turkey baster to suck up a cloud and replace the water with boiled/cooled aquarium or rainwater.


Newly set up Infusoria culture

Alternate method – adapted from BKA Information Pamphlet No. 14 August 1966 by George J. Maier. Chicago U.S.A.

A short look at their way of life will help a great deal in Infusoria propagation. The most suitable Protozoa is unquestionably Paramecium. They multiply by cell division and feed on the rod-shaped bacteria that are always present in immense numbers when organic matter is decaying in water. If ample food is present, they multiply in astronomical proportion. Dr. Ehrenberg figured out that a single Paramecium could grow into 70 million individuals in 30 days under favourable conditions. Because of its body shape it is very often called the slipper animal.

Rotifers, on the other hand, are many – celled animals. They have a heart, a stomach and digestive tract and reproduce by laying eggs. In size they are larger than the previously described animals and for this reason can be considered a very good food animal for our young fish. The name Rotifer, or wheel animal, is derived from the fact that on either side of its “head” are cilia that are moved very rapidly so they appear to be on a moving wheel. The ones on the left side of the mouth move clockwise and those on the right side anticlockwise. This motion brings a stream of water to the animal’s mouth. Most animals go after food, our Rotifers create a current that brings their food to them. In a young culture Paramecium are found in greatest abundance but as the culture gets older the Rotifers will take over. For practical purposes we can utilize this knowledge by feeding newly hatched fish water from a new culture and as the fry grow, we feed them from the older culture containing mostly Rotifers. The easiest to raise Rotifer is Philodina.

The practical way to get a culture started is by filling a wide mouthed gallon jar with water from the hot water tap. Let it cool off and then add a piece of dried lettuce, about the size of a dollar bill or pound note. Now for the next three days check the pH every day, it should be alkaline, If it is not, correct this with small quantities of Sodium Carbonate (Baking Soda). After the third day a small quantity of water from a known culture is added and you are in business. Once the culture is going there is no need to worry about pH, the culture will always stay on the alkaline side unless it is polluted with too much lettuce. Once the dried lettuce sinks to the bottom it should be removed and replaced as its food value has gone. The culture should smell like stagnant pond water, it should never stink. If it ever gets foul through neglect the sediment should be syphoned off and the culture aerated for a short time. This generally takes care of the bad odour.

You feed this culture to your young fish by giving them as much as they will eat, for instance, for 300 angel fish fry, feed about 4 ozs. of the liquid. You can see the infusoria readily with your naked eye in your tank and once they are gone, they should be replaced by more. Young fish should always have food in front of them to ensure maximum growth. On the other hand, if we over-do it and put too much infusoria culture into our tank water, we are liable to deprive our fry of the needed oxygen. Common sense should be your guide here.

The cultures are kept on a shelf at room temperature. If for any reason you do not need your culture because you have no young fish to feed, you may forget about it for as long as two months. If again needed, draw off the sediment from the bottom, replace the water, add dry lettuce and in two weeks’ time you will have a good culture again.

As you noticed I use dry lettuce. This I do for convenience. Whenever we have lettuce on the table the outer leaves are usually discarded. In our household they are dried and put into a plastic bag. You could use alfalfa, dried banana peels, rice, wheat or almost anything that will decay, and it will do the trick, but I have had the best results with dried lettuce.

I make it a practice of always using water from the hot water tap. Just about all animal life is killed off in the hot water tank, that way I do not introduce unwanted animals into our culture.


Culture Techniques of Infusoria