How to Culture Microworms for Fish Fry
Because of their attractive movements, live foods can be very useful in breeding fish. They encourage babies to eat more and grow faster. 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?
Microworm is the common name for a roundworm or nematode found in Panagrellus. The most popular types used in the aquarium hobby are (in order of smallest to largest):
– Panagrellus nepenthicola – Walter worms – Panagrellus silusioides – Microworms – Panagrellus Redivivus
They are about 1-3 mm long and approximately 50-100 nm in diameter. This is slightly less than vinegar eels. (By contrast, the size of newly hatched brine shrimp is 450 microns. This means that even tiny fry can eat nematodes like noodles. When they reach maturity, female roundworms are usually 3-4 days old. They can produce 300 to 1000 live young each year, depending on which species.
Close-up of banana worm versus micro worm starter cultures
How to Start a Micro Worm Culture
Banana, walter, and micro worms are almost identical in their care requirements, so the rest of the article refers to all three types of roundworms generically as “microworms.” Do not use the following instructions for grindal or white worms, which are annelid worms and need a different kind of setup.
1. The following materials are required:
– Starter culture for micro, banana, and walter worms. – A box of plain instant mashed potatoes. – Several small plastic tubs, deli containers, approximately 5 inches (13cm) in diameter, with higher sides and tighter fitting lids. – Dechlorinated Water at room temperature
1. Cover the bottom with a layer of mashed potatoes flakes, about 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: Adding yeast to the culture does not seem either to aid or hinder its growth. Also, we prefer to use instant mashed potatoes or baby cereal because they don’t produce a smelly odor like oatmeal and some other mediums do.
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 prevents flies or other pests from entering the container. Cover the container.
Notice: Some people prefer to cover all of the holes in the lid with a pillowcase, even if they are making a bigger worm culture.
1. Label the culture with the type of roundworm you’re using, as well as the date it was created because the cultures have an expiration date (see below). The container can be stored at ambient temperature. 2. To make multiple microworm cultures, repeat Steps 2-5. You should have backups in case the original medium becomes spoiled, moldy or infested.
How to Harvest Microworms for Fish Feeding
Some worms may climb out of the medium onto the walls and make it easier to collect them. To clean the sides and bottom of the plastic tub, use your fingertip or a cotton swab. 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
The culture will become more and more contaminated with worm poop over time. This makes the culture very thin. Repeat Steps 2-5 above to create a new cultural unit. Add one spoonful of worms to the existing 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. Learn about how to hatch your own brine shrimp in the article linked below.