This material is from the 4th edition of The Zebrafish Book. The 5th edition is available in print and within the ZFIN Protocol Wiki.


Simple, Quick Methods For Raising Paramecia

(Source: R. Kimmel and S. Johnson)

Paramecia multimicronucleatum can be obtained from Carolina Biological Supply or Connecticut Valley Biological. This strain of very large paramecia promotes rapid growth of the fish larvae. The following method of growing the paramecia is simple, quick, and very suitable for small, low-budget, fish-raising as well as for a large facility.

Grow seed cultures in 150 x 25 mm plastic petri dishes at 28.5C. In addition, grow several small batches of seed cultures in other rooms at room temperature as a back-up in case of a (rather rare) "crash" in the fish facility's paramecia population. These cooler cultures grow slowly and need care only every four or five weeks.

Paramecia seed cultures:

To petri dishes:

1. Add 175 ml double distilled water, about 10 boiled wheat seeds (animal feed wheat or health food store "wheat berries"), 1/5 of one 7.5 grain standard brewer's yeast tablet, and approximately 10 mls from a good clean young paramecia culture.

2. Stack the petri dishes 3 or 4 high and store at 28.5 in a lighted place. The cultures will be ready to use in 2 days and will keep for several weeks. One seed culture will start 10 new seed cultures or six 2-liter pots for baby fish feed.

Standard paramecia recipe

1. Fill each 2 liter amber mouse cage (actual capacity 2,750 ml) with 2 liters of system water

2. Add approximately 30 seeds of boiled wheat, 1/2 tablet of brewer's yeast, and 1/6 of a petri dish of paramecia seed culture

3.Cover and stack the mouse cages and store in the light at approximately 28.5.

The cultures will be ready for use in 4 days and will keep for about 3 weeks.

Growing small batches of paramecia

1. Use glass finger bowls filled two-thirds full with system water.

2. To each bowl add 8-9 grains of boiled wheat, 1/5 of one 7.5 grain brewer's yeast tablet, and 8 ml from a paramecia seed culture.

3. Stack the finger bowls 6 or 8 high, cover, and store at 28.5C on well-lit shelves.

4. After 14 days, the paramecia are ready to feed to the fish larvae. Cultures remain useable and healthy for 3 weeks or more.

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