How to Culture Microworms for Fish Fry
The attraction of live foods is a great way to breed fish. It encourages the babies’ growth and eating habits. However, some fish (such as betta fish, ram cichlids, and rainbowfish) produce miniscule offspring that are too small to eat traditional fry foods like live baby brine shrimp or crushed flakes. You can instead start a micro, walter, or banana worm farm to keep the babies happy.
What are Microworms?
Microworms are nematodes or roundworms found in the Panagrellus Genus. The most popular types used in the aquarium hobby are (in order of smallest to largest):
– Banana worms (Panagrellus nepenthicola) – Walter worms (Panagrellus silusioides) – Micro worms (Panagrellus redivivus)
They range in size from 1-3 mm in length and roughly 50-100 microns in diameter, which is slightly bigger than vinegar eels. (By comparison, brine shrimp that have just been hatched are approximately 450 microns long, so even the smallest fry can eat nematodes as noodles. Female roundworms reach maturity when they are 3-4 days old and can produce 300-1000 live young in their lifetime, depending on the species.
Close-up of banana worm versus micro worm starter cultures
How to start a micro worm culture
The care requirements for micro, walter and banana worms are nearly identical. Therefore, the remainder of this article will not be applicable to white or grindal worms. These worms are annelids and require a different type of setup.
1. The following materials are required:
– Starter culture of micro, banana, or walter worms. (purchased at a fish club auction or local fish store, AquaBid.com or another online source). – A few small plastic tubs/deli containers measuring approximately 5 inches (13 cm) or larger with taller sides. – Dechlorinated water at ambient temperature
1. To cover the bottom of your plastic container, add a layer of mashed potato chips measuring 0.5 inches (1.5 cm). Mix the mixture with a little water until it becomes light and fluffy. You don’t want the mixture to be too wet or soupy.
Note: We have found that yeast does not appear to affect the growth of the cultures. We prefer instant mashed potatoes and baby cereal over other options because they don’t have the same smelly odor as oatmeal or other mediums.
1. Pat down the mixture until it is spread evenly in the container and then add a spoonful of the starter worm culture. Spread the worms out onto the medium.
1. You can make a small opening (approximately 1cm x 1cm) in the middle of the lid with a razor blade, hole puncher or hole saw. This will allow the roundworms to breathe. Cover the hole by attaching a patch of fabric to it or stuffing it with filter floss. This will prevent flies and other pests entering the container. Close the container.
Notice: When you’re making a large worm culture, it is better to wrap the entire tray in a blanket than cover the holes in its lid.
1. You should label the culture with the roundworm type you are using and the date it was made. Cultures have an expiration date (see below). The container can be stored at ambient temperature. 2. Repeat Steps 2-5 to create multiple microworm cultures, just in case one of the cultures crashes. You should have backups in case the original medium becomes spoiled, moldy or infested.
How to Harvest Microworms To Feed Fish
Some of the worms will start climbing out of the medium and up onto the walls, making it easy for you to collect them. Simply use your fingertip, a cotton swab, or a cheap children’s paintbrush to wipe along the sides of the plastic tub. For fish to eat, you can dunk the worms in the tank. Micro worms can live for between 8-12 hours in water. To avoid problems with water quality, do not feed them too much. It’s okay if a little potato mixture gets into the aquarium because the omnivore fish will eat it along with the roundworms.
Hobbyists have learned that only feeding microworms can sometimes lead to deformities, either from nutrient deficiencies or water quality issues, so make sure to supplement your fish’s diet with other high-quality foods like Hikari First Bites and Easy Fry and Small Fish Food.
How to maintain the micro worm culture
Over time, the culture becomes more and more filled with worm poop, making the medium very runny in consistency. Make a new culture by repeating Steps 2-5 from the above section and adding one spoonful of worms from the old culture. We recommend that you switch to baby brine shrimp once the fry have grown sufficiently large. They are high in protein, fat, as well as nutritional content. Find out how to make your own brine shrimp by reading the article linked below.