California Blackworms

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• Intro
• Buying
• Care / Maintenance
• Culturing

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Ok... Technically, this article is not so much about "Culturing" them as it is about "Maintaining" them. I.e. keeping them in tip top shape for your fish. I will touch a little bit on how to culture them below, but IMHO, for most hobbyists, it is just not worth the time, effort and space to culture them, because it takes a lot to raise them in any appreciable quantity.

Anyway, California Blackworms (CBW), if maintained carefully are some of the best freshwater live foods that you can get out there. Their wiggling action triggers predatory strikes in even the finickiest fish. Hence they are the perfect foods to feed fish that have gone off their feed, or for use when weaning wild caught fish onto dry foods. Although I do not recommend using CBW as the staple food for any fish, but it is good for an occasional treat.

INTRO

Correct me if i'm wrong, but true "California" Blackworms are only grown in California (duh!!), and only by AquaticFoods in Fresno California. In fact, it is the company's proprietary name for that particular type of worm (just like how we call all brands of boxed tissues "Kleenex" or all brands of in-line-skates "rollerblades"). Dan from Aquaticfoods assures me that although there are lots of '"posers" out there, that 99% of all the "Blackworms" in the U.S. comes from his farm. (Which shows you how even a little worm can change your life forever).

Some people are wary about feeding their beloved fish any live foods for fear of disease. While I acknowledge the possibility of a diseased morsel of live food killing your fish, I have found that 80% of the time, it is absolutely preventable or is directly a result of either the oversight or the inexperience of the aquarist. 

ALL live foods carry the risk of infection, if it is alive, there is a possibility that it may be sick. The onus is on WE, the buyers to minimize the chance of bringing home a disease. Some people buy live food from unreliable sources or buy live food that is clearly sickly without recognizing the telltale symptoms. These telltale symptoms vary between the different live foods. My advice is BEFORE bringing that bag of worms home to your hungry fish, do as much research on that food AND food source so that you can immediately spot sickly food.

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BUYING

The good thing about AquaticFoods, is that unlike most other large suppliers, they will gladly take orders from hobbyists. You can go to their website, place an order and have a box of worms shipped to your doorstep next day. But unfortunately, like most suppliers, their smallest quantity available is a 3/4 lb box which is A LOT of worms. This is great if you have a hoard of hungry mouths to feed, or place a group order with your local hobbyists. For the rest of us who don't need that many worms, we might need to get it from the LFS.

IMO, there's nothing fresher than getting live foods straight from the supplier. After all, chances are that the LFS also got the worms from the same place, so you're bypassing a step in the supply chain. Besides, who knows how long the worms have languished at the LFS before you buy them or even if the LFS is even doing the required daily water changes to keep them fresh. But if you have to buy from an LFS, here are a couple of pointers for you to get the healthiest worms.

1. Make sure that your LFS gets their blackworms from a reputable source.

2. Ask to see the worms before you buy them. If the store refuses… walk away.

3. Inspect the worms carefully. Worms should be stored in a shallow container and kept chilled in the refrigerator. Worms should be fat and dark colored. Thin worms indicate that they have been kept in the fridge for a long time. An occasional light colored worm is acceptable. Look for dead worms… if you see a lot of dead and discolored worms, walk away.

4. Worms should be lively. Ideally the moment the refrigerator door is opened, you will see the worms react suddenly. If worms are lethargic, walk away.

5. Optionally, you may ask if you may touch the worms. Gently place your finger on top of a mass of worms or tap gently on the container that the worms are housed, if they react suddenly to your touch / tapping, they are healthy. If worms are lethargic, walk away.

6. Finally, if possible give the whole thing a sniff… if it smells bad, it probably is bad. Walk away.

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CARE / MAINATAINANCE

When you get home, immediately rinse the worms out with de-chlorinated tap water at room temperature. Carefully decant away any dead or sickly worms. Worms may be stored in a Tupperware with ½ inch of de-chlorinated water covering the worms. Store in the fridge without the Tupperware top. The worms shouldn’t climb out, but if they do, then you have something wrong with your water and they are trying to escape. Check to make sure that it is aged de-chlorinated water and it does not cover the worms by more than ½ inch.

EVERYDAY… take out the Tupperware and rinse the worms with de-chlorinated water, again carefully decanting away the dead and sickly. You will quickly notice that dead and sickly worms tend to float while healthy worms sink to the bottom real fast, which makes it easy to pour away the bad stuff.

I have kept worms like this in my fridge for as long as 4- 5 weeks with no ill effects. Beyond that, I would recommend tossing the batch and getting new stuff.

Worms in the fridge.

Update!! - "Worm Keeper" Review.

Recently, AquaticFoods has put out a nifty new "Worm Keeper" that I have been trying out. It's basically a very fine micron mesh bottomed tray that nests in another larger box. The mesh is large enough to allow water flow through it, but small enough to prevent most of the worms from going through it.

Worms are easily lifted out of the wormkeeper container, leaving the nasty water behind:

Fine Mesh in the worm tray prevent most worms from going through:

My wormkeepers came without instructions, but it is pretty clear that the worms go into the meshed tray and that in turn goes into the larger box. What took some figuring out was how to do my daily rinsing with those things. At first, I merely lifted the worm filled tray out of the water, and then rinsed the worms through the mesh before replacing them into the large box of clean water. However, I find that that I am not able to remove the dead and dying worms efficiently. Besides I found that despite the small mesh size, there were still worms able to squeeze their way through the mesh and end up at the bottom of the larger box.

I played around with different methods and still came back to the "decant" method similar to the tupperware method :

1. Lift the meshed tray out of the box and place in the sink (or anywhere you don't mind CBW juice).

2. Discard old water and rinse out the box under the tap. If there are worms at the bottom of the box you want to save, carefully decant away the water, retaining the worms at the bottom of the box.

3. Pick up the tray from the sink and (with a good flick), overturn the tray on top of the box, dumping as many worms as you can into the box. Some worms will still stick to the tray, rinse these into the box with dechlorinated water.

4. Rinse the now empty tray under the tap, scrubbing whatever slime buildup that may have accumulated. Set aside for now.

5. Fill the box with dechlorinated water and agitate the water with your fingers or a stirring spoon. When you stop , you will begin to see the healthy worms sink to the bottom and dead and dying worms remain longer in the water column.

6. Decant away all the sick and dying while retaining the healthys. Repeat step 5 & 6 as many times as you want.

7. Pour the worms out of the box and back into the meshed tray. Replace the tray into the box and top up with enough water to cover the worms with 1/2" of water.

8. Place back in fridge.

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CULTURING

Well, since somebody asked, I shall oblige. Sorry I don't have pics for this because it's been a while since I attempted this and it probably didn't occur to my dumb brain to take pictures of this back then.

The method that I describe was done at a small scale and produced only a small amount of worms every week (enough for a quick snack pretty much), but that's not to say that if you manage to scale it up that it won't produce a good amount of worms. Experiment around and let me know. I'm going to describe the simplest setup that you can put together, but feel free to make it as complicated as you wish.

For materials, you'll need

• 10 gal aquarium (or larger if you wish, but use aquariums that are long as opposed to tall because worms live on the bottom and prefer floor space to tank height).

• Culturing medium - Plant based burlap. Basically its sackcloth, the same bags that we used to do potato sack races in. Occasionally you'll be able to find some at construction or farm supply stores. Make sure that your burlap has not been previously treated with chemicals or such. It should be in its natural brown color and not bleached white or colored. If you can't get burlap, you can substitute with heavy duty brown paper grocery bags. The paper bag works, but it is very much more messier than burlap because it eventually breaks up and forms a papery mess at the bottom of the tank. Good luck trying to harvest your worms from this....

• Airstone + air pump. DO NOT USE A SPONGE FILTER!! Worms will eventually make their way into the filter and you'll end up with a clogged sponge full of worms which you cannot harvest.

Cut up your burlap into 2" to 4" pieces (strips or squares don't matter). Enough to cover the bottom of the tank with 2 or 3 layers of burlap. Place the burlap in the tank and fill with water to the top. Sometimes the burlap takes a while to sink. You can speed this process up by boiling the burlap pieces before placing in your tank.

Fill the tank with dechlorinated water. Or better, fill half with dechlorinated tapwater and the other half with old tank water from a previous water change from your other tanks. Its okay to have some mulm which you may have vacuumed out of your old tank. In fact the worms seem to love that stuff.

Hookup the airstone to the pump and place into the tank. Adjust so that the current generated is enough to circulate water around the tank, but not so strong that it blows the burlap (and worms) around. The burlap should sit stationary at the bottom of the tank. Then take a tablespoon or so of blackworms and seed the culture. The worms will burrow into the burlap and inter weave themselves with the fibers of the fabric. You'll notice that as the culture settles down, that the worms will start poking their heads (or tails) out from the burlap and point them straight a the ceiling.

To feed them, just crush up some flake food and scatter it all over the water column, making sure that all the "floaters" sink to the bottom. I haven't yet figured out what the optimum feeding regime is yet, but i just feed them whenever the flake disappears. Usually every 2-4 days or so.

Blackworms living in the substrate:

To maintain the culture, i do weekly 25 - 50% weekly water changes using a python and a bucket. I plunge the end of the python into the bottom of the tank, pressing the burlap against the bottom of the tank so that it doesn't get sucked up into the tube. If done correctly, a cloud of gunk should get sucked out through the burlap while leaving the fabric in place. Another way would be to vacuum the burlap through a net. Place the end of the python into a net and vacuum through the netting. Occasionally blackworms will get sucked into the python and end up in the bucket. You can catch the worms with a net or a micron mesh on the other end of the hose. These will make a nice snack for your other little critters.

Eventually, even burlap breaks down and the pieces come apart into individual fibers. You may pick these fibers out with plant tweezers and replace with new burlap.

I haven't figured out the best way to harvest these yet, definitely let me know if you do! Basically i take a bunch of burlap from the bottom of the tank and place it in a fish net (or a large micron mesh if you can build one with PVC and mesh). Then i place the net in a bowl of water. The bottom of the net (with the burlap) should be entirely submerged but not resting on the bottom of the bowl. I leave this overnight. Try to pick out as much "empty" burlap as you can out of the net before letting it sit. This will encourage the worms to migrate out of the net. Hopefully, the worms will make their way out of the burlap, through the net and fall into the bottom of the bowl where they will be waiting for you in the morning.

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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 to include much more aquarium related information. 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 GoogleAds 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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