How to Culture Infusoria

Infusoria is a collective term for microscopic aquatic creatures like ciliates, euglenoids, protozoa, and unicellular algae that exist in freshwater ponds. Aquarists feed infusoria to their tiniest fish fry, such as Neon Tetras, Gouramis and Betta, for them to survive their first few days. However, there are usually not enough infusoria in the average aquarium tank to feed the newly hatched fish. So here is how you can start and maintain your own infusoria culture indefinitely - ready at a moment's notice to feed your young fish. Get your microscope or loupe out, put on your white lab coat, and re-live the days of Biology 101! :-)

Difficulty: Easy

Instructions

Things You'll Need:

• 4 1-quart canning jars
• Aged, aquarium or pond water

1. FILL THE JARS HALF-FULL WITH AGED WATER -- If you have an aquarium or an outdoor pond, use water from that. I have even used water from a plant vase -- there are likely lots of infusoria in that! Do not ever use tap water -- it has chemicals in it meant to kill infusoria!

2. 
    
   The rotifer is a favorite fry food.

   CREATE AN INFUSION -- You're creating food for the bacteria that infusoria eats! Aha -- you didn't know you were creating your very own food chain, huh? Biology 101. :-) You can boil hay or grass in water and use the cooled “tea.” Or one rabbit food pellet per jar could be used. Some infusoria growers puree lettuce leaves, and some squeeze a handful of aquarium plants (and infusoria). Use your imagination.

3. ADD THE COOLED INFUSION TO EACH JAR -- Let the jars stand for several days. Do not place them in the sun, but the warmer the water (up to about 80F), the faster the cultures will grow.

4. CHOOSE YOUR BEST CULTURE -- Shine a flashlight into each jar and look for cloudy water. The dust-sized particles are your infusoria. Pick your best culture and clean out the others. Start new cultures and inoculate them with your most successful culture.

5. 
    
   Apple (or Mystery) Snails will indirectly create food for the infusoria.

   MAINTAIN YOUR CULTURES -- Infusoria eat even tinier bacteria. When you feed the bacteria, you're indirectly feeding the infusoria. Use your infusion water - or a tiny dab of powdered eggs or brewer's yeast makes a great food. If you're getting the Biology 101 bug, add some lettuce leaves and Apple snails or Colombian ramshorn snails, which eat large amounts of plant matter and their digested waste products will jump start and feed an infusoria culture. Your kids will be learning something as you feed your fish!

6. FEED YOUR FISH FRY -- Pour most of one of your infusoria cultures into your fry tank. Then add more water and powdered egg to restart your infusoria culture. This is why you have more than one culture jar going.

Tips & Warnings

• If one of the jars becomes stinky, you have dead infusoria -- dump it and start it again with one of your good cultures.
• Do not use tap water, it kills infusoria and the bacteria it feeds on.

Resources

• Wiki article on infusoria
• Aquarium wiki on infusoria

[dlcass]

on 11/28/2008 Biology 101, I LOVED that class : )