Microworms, Panagrellus redivivus are another wonders to fish breeders. They are cheap, convenient and reliable. They are high in proteins and fats, which is ideal for fry. Microworms are easily cultured on oatmeal mash. They grow rapidly, each worm reproducing in 20 hours under ideal conditions. The younger stages are smaller than newly hatched brine shrimp and they are taken eagerly by almost all species of fish. Microworms are an excellent choice for small egglayers fry. After 2 weeks of life feeding on infusoria, the fry get large enough to take in microworms or newly hatched brine shrimp.

Culturing Microworms

To culture the worms, make a stiff paste of instant oatmeal (2tsp.) with a little dried yeast (1/4 tsp.) added. Add enough boiling water to make a very stiff paste, then place this in a suitable container. Make a few holes in the lid for ventilation. Allow to cool to room temperature then add a small inoculum of worms from a mature culture.

When they grow, the worms can be harvested by scraping them off the sides of the container with a wooden stick or wiped with finger. Add direct to the fry tank. Be careful not to touch the culture medium, which will foul the water. Cultures will last for about 2 weeks. As long as the culture stays fresh, there will be no bad smells, but when the odour increases and production decreases, its time to start a new culture.

Although microworms do not swim, they are kept in suspension by even modest aeration and so are available to fry which feed in midwater. You may want to keep your fry tank devoid of gravel, so the worms don’t disappear from the hungry babies. Alternatively, you can use a feeder made from a small floating plastic container with pinholes in the base. This will release worms slowly into the water column over a number of hours.

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