Culturing Microworms

Author: Rob Torrens

Microworms, as the name indicates are a very small worm (in this case a nematode type worm). Their size makes them useful for feeding to fry and fish that have a small adult size. They can be easily cultured and harvested. A number of hobbyists interested in breeding fish keep these worms - so if you ask nicely you may get a sample to seed your own culture, or alternatively cultures are available from Biosuppliers (a NZ based biosupply house).

The culture medium

There are a couple of different mediums that can be used for microworms, but the one detailed here is the one I use regularly (I also use it for wingless fruitfly).

A mix of rolled oats and cornmeal (in about a 2:1 ratio) are ground into a coarse powder using a kitchen blender (this step is not essential, but I prefer to have a fine homogenous mix). About 0.5-1 cm of this mix is placed in the bottom of the container and boiling water poured over it (enough to wet the mix, but not too much) to get the 'porridge' mix to gel. Once this mix has cooled, sprinkle over some yeast (just ordinary bakers yeast is fine) and add the microworms.

Harvesting and Maintenance

As the microworms multiply they will form a layer up the sides of the container, this can be easily scraped off and feed to the fish.

Cultures do get tired, as evidenced by the lack of microworms climbing the side of the container. Drying out of the medium can sometimes be a problem (so lightly mist the culture), but lack of food is more likely - so try sprinkling some more yeast over the culture - if this doesn't get the culture going again then it is time to start a new one.

If there is still movement in the culture then you should be able to start up a new one. Just take a small spoonfull of the 'goo' and use it to seed the new culture.