Culturing Vinegar Eels

To start out, here’s a quick video guide on how to culture vinegar eels:

Vinegar Eels make a great fry food, especially for very small fry that are not big enough to take microworms. Like Microworms and Walterworms, they are nematodes; however, they are smaller than either. They can also be maintained in VERY low maintenance conditions.Unlike Micros or Walters, They DO NOT require sub-culturing every couple of weeks. Basically, all you need is a glass or plastic container, (1/2 gallon or 1 gallon is supposedly best, but 2 liter is fine) a 50/50 solution of apple cider vinegar and distilled or R/O water, and some chopped apple.For more detailed instructions, see below. They are not as prolific as Microworms or Walterworms, nor should they be used as the sole diet for more than a few days, but they are a great food to have on hand for those surprise batches of fry, or for fry too small to take microworms.

How I Culture Vinegar Eels

click here to listen to the podcast on culturing vinegar eels

You will need:

A container (plastic or glass; can be as small as a quart or more than a gallon. Larger cultures are more productive and, in theory, less prone to crashing.)

A lid for the container. (This should allow for ventilation, but not large enough to admit vinegar flies. I have found that drilling holes in the lid and plugging them with aquarium filter padding works well.)

Apple cider vinegar

distilled or R/O (reverse osmosis filtered) Water

Pieces of fresh apple and/or apple juice

Your starter culture

  1. Modify the lid of your container as above to allow for ventilation. If you do not cover the container, it will eventually attract fruit and/or vinegar flies.
  2. Fill the container with a solution of approximately 50% apple cider vinegar and 50% distilled or R/O water. Leave an inch or two of air space a the top of the container. You may substitute apple juice for some of the water if you wish. In fact, some people use 100% vinegar. Vinegar eels are pretty tough.
  3. Chop the apple into small pieces. Exact size in not critical. Add some bits of apple. About ¼ to ½ apple per culture is enough.
  4. Add your starter culture.
  5. Put the lid on the culture container.
  6. You will need to wait a couple of weeks for the worms to reach a density sufficient to enable harvesting. There are myriad methods of harvesting available on the internet, but I prefer to scrape them off of the sides of the container when they form clumps. Sanding an area of the inside upper surface of the container with a fine grade of sandpaper prior to starting the culture is supposed to encourage this.
  7. It is a good idea to have more than one culture on hand in case you experience a crash, but vinegar eel cultures are quite resilient. An individual culture lasts much longer than a microworm or walterworm culture. They also appear to produce fewer worms.

Tips:

Harvesting

You will need to wait a couple of weeks for the worms to reach a density sufficient to enable harvesting. There are myriad methods of harvesting available on the internet, but here are the basics:

  1. After a couple of weeks, the worms begin to form clumps on the sides of the containers. Iscrape them off of the sides of the container when they do this, using a cotton swab. This was not my idea. I found it at http://www.waynesthisandthat.com/eels.htm.Sanding the container with a fine grade of sandpaper prior to starting the culture is supposed to encourage this clumping behavior. I also find that they do it better in flat-sided containers rather than round ones. With this method, the small amount of vinegar you collect will not do any harm when added to the fry tank.
  2. Suck up several droppersful of worms and culture solution and expel them into a coffee filter. Let the vinegar drain out, leaving the worms for feeding. It is said (I can’t recall where) that some of the smaller worms are lost with the drained vinegar this way.
  3. Some people use a narrow-necked bottle and a wad of filter floss. You fill the bottle with worm-rich culture solution and plug it with filter floss, leaving the narrow neck empty. Next, pour aquarium water on top of the filter floss. Within a few hours, the worms work themselves up into the aquarium water. You can then suck this wormy water up into a dropper and feed it directly to your fry.

Shipped on a filter pad?

Vinegar eels can be shipped in a variety of ways. Since the post office is sometimes uncomfortable about shipping liquids, I often ship on a small piece of blue filter floss material. To seed it with worms, I hang it in the culture container by a thread. The worms are attracted to it, and I haul it back up and put it into a plastic bag. To introduce the worms into your culture, (assuming the temperature of the starter culture is already similar to that of your main culture container) simply lower the damp sponge into your culture and swish it around. The worms will swim out into the culture medium. You can save any worms that may have stayed in the baggie by swishing it out with water, apple juice, or vinegar and pouring the stray worms into your main culture.

Have a backup

It is a good idea to have more than one culture on hand in case you experience a crash, but vinegar eel cultures are quite resilient. An individual culture lasts much longer than a microworm or walterworm culture. They also appear to produce fewer worms., but enough for what you need them for.

© 2008 by R. Max Wilson

RESOURCES

http://www.waynesthisandthat.com/eels.htm

http://www.skepticalaquarist.com/docs/feeding/vinegareel.shtml