Microworms / Walterworms

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For the longest time, I had assumed that Walter Worms and Microworms were the same thing. After all, they look the same and are used interchangeably to feed fry. But we now know that they are different. The most appreciable difference for us aquarists is that Walter Worms tend to "swim" in the water column for longer periods than the sinking microworms. Hence, Walter Worms may be fed to fry who tend to hover at mid depth to the surface, while microworms are perfect for fry that like to sit at the bottom. Here's an article that I found on Diane's Live Food Culture Page with a pretty well documented experiment of this. Because i use them mainly on Bettas, I now only keep the "Walter" variety.

CULTURING
Culturing them is pretty simple. First you need some sort of container. Margarine containers, and disposable "pop-top" containers work great. I wouldn't use the expensive stuff like tupperware or what not as the containers will be thrown away after a couple of rotations. Since the worms live pretty much near the surface of the culture medium, it is better to get something that has lots of surface area compared to the depth of the medium. I like to use disposable plastic lunch containers with the tops perforated with small holes to allow breathing, but small enough to keep flies and other creepy crawlies out. Here's a pic of my culture container:

Next, you're going to need some culturing medium. I've tried mediums such as corn meal, potato flour, oatmeal, wheat flour, mashed bananas and baby cereal, with varying degrees of success, but all had the same fatal flaw. They STANK! I would usually get used to the stench, but would always be reminded when I have visitors. But this was before I discovered this:

I'm convinced that this is the holy grail of microworm culture. I'm able to have culture going 2 weeks (typical rotation time) while avoiding the normal putrid smells. Ever since I switched to using mashed potato flakes, I no longer get comments from my guests.

Simply mix the potato flakes with hot water until the desired consistency is obtained. I typically keep my mashed potato on the thicker and dryer side, as opposed to thin and fluid. This is because as the culture matures, the whole thing will become more and more fluid. Hence i start off with a relatively thick mix. If it is to watery, add some more flakes. If it is too dry and crumbly then add a little water. You want to aim for a smooth texture that won't run when you try to scoop it up with a spoon. It should look somewhat like the mashed potatoes that you would serve at the dinner table.

Spoon the mixture into your container and set it aside to cool. Only introduce the worms from the old mixture when the new mixture is sufficiently cooled. Store in a cool place. Lighting does not seem to affect reproduction, so you can store them in the dark or in the light. Just make sure that the mixture does not become overly dry. If it dries out too much, just mist it lightly with a spray bottle filled with dechlorinated tap water. After a week, you should see worms shimmering on the surface and start to crawl up the walls:

In my opinion, there is no necessity to add yeast to each new mixture. Some people say that the worms actually feed on the yeast but I haven't yet found any evidence to show this. Even if you obtained a culture which had some yeast, if you add portions of an old culture to a newly mixed medium, you can be sure that some yeast will be transferred to the new culture, kinda like making sour dough bread. Eventually the yeast will reproduce in the new culture, so there is no need to keep adding yeast after every new culture.

HARVESTING
There are many methods to harvesting microworms / walterworms which are very well documented online. My preferred method requires a 3mL dropper (disposable pipette) and a clear plastic cup of dechlorinated water, clearly labeled that it is for "Microworm Use Only". (Lest anyone pick it up and actually drinks out of the cup).

I get enough microworms/ walterworms to feed my fish by simply running my finger around the walls of the container like in the video above. Then I swirl my finger in the water to wash all the worms into the water. I let it sit for about five minutes to "clean" the worms a little bit. Then I use the pipette to suck up the worms, which i can now use to target feed my fry:

But if you need to harvest lots of worms, check out Wayne Schmidt's article.

I typically keep 2 sets of cultures going, each spaced a week apart, just in case something goes wrong and I lose a set of cultures. I keep each set of cultures for 2 weeks before throwing it away and starting a new set of cultures.

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PLUG

On the urging of my friends, I started this website by putting together the original (and quite successful) B. Macrostoma pages. Since then it has grown by quite a bit. All this time I've provided all this info and lots of free e-mail support to anyone who needed help. The advertising on this page helps out a little to offset the cost of webhosting. So if you see something that you may be interested in listed within the Google Ads banners, then please don't hesitate to check it out.

I thank you all for your great interest in my articles and I hope to keep hearing from you guys, even if it is just dropping me a note to say hi. God Bless!

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