Remember me

[ ]
Main Menu
· Home
· Forum
· CAKC Officers
· CAKC By-laws
· Join the CAKC
· Article Library
· Links
· Photo Album
Forthcoming Events

See our 2019 Calendar

19 Oct - CAKC meeting hosted by Cris Diaz, Aberdeen, MD 21001

For Club details contact Cris Diaz - diazcva©aol.com

Vinegar Eels

Vinegar Eels
by Adrian R. Tappin
reprinted with permission
Orinigally published at: http://www.powerup.com.au/~tappin/

Borellus discovered the vinegar eelworm Turbatrix aceti in 1656. It is a free-living, non-parasitic round worm that is adapted to living in a low pH (acidic) medium and are an excellent live food for rainbowfish fry. Vinegar eels are readily cultured in large numbers, provided certain simple procedures are followed. They must be grown in natural cider vinegar that has not been chemically treated to inhibit growth of bacteria and yeast upon which the worms feed. The vinegar can be used either pure or diluted with 25 to 50% water. The periodic addition of a small piece of apple seems to add something that causes a greater population of worms, but is not absolutely necessary.

Add your vinegar eel culture to approximately 500 ml of culture medium in a glass jar covered to reduce evaporation. Punch small holes in the lid (cover) for aeration. Cultures should be maintained at 20-30°C and subcultured every 6-8 weeks to fresh medium. Vinegar eels can rapidly increase in number and females with developing embryos can be found within one week of starting a new culture. Embryonic development takes about eight days from time of fertilization of the egg to time of birth of the young.

Harvesting of the worms may test your patience until you have developed a procedure to collect them, as it is very important not to get any culture medium in the fry tank. The most common method to harvest the worms is to pour or siphon the culture medium through a laboratory or coffee filter-paper and in so doing collect most of the worms. Return the medium back to your culture container. The filter-paper with the collected worms is then rinsed into a jar of clean aged water and can then be poured into the fry tank. The worms will live for a long time in the tank but care should be taken to prevent supplying too much worms at one time.

The advantage of feeding vinegar eels is:

Vinegar eels will live for a long time in the aquarium water.
Vinegar eels swim in the water column and stay towards the surface where rainbowfish fry feed.
Vinegar eels are just a little smaller than micro-worms, a great size for most baby fish.
Vinegar eel cultures require little attention (indeed they can be ignored for weeks at a time)
Vinegar eel cultures don't "go off" leaving an unpleasant smell.

Starter cultures can be obtained from biological supply companies, aquarium shops or fellow hobbyists. The only drawback with vinegar eels is the harvesting method required - but it's well worth the effort.

Wright Huntley, from Fremont CA, USA sent me the following method he uses to culture and collect the worms:

Some European correspondents had mentioned separating the worms from the vinegar in test tubes. Vinegar/culture medium on the bottom, some filter floss, and clear water on top. The worms seeking oxygen move up through the filter floss to be near the surface. Very effective, but not enough worms to feed many fry.

Wright modified the technique and finally made it productive enough to be useful. He uses long neck bottles for culturing, plus a couple of spare plastic juice bottles for extra culture medium.

Keep the culture medium level well below the neck to have adequate surface area. To harvest, remove the floss plug and add enough spare culture medium from the juice bottle to reach above the bottom of the narrow neck. Push the polyester filter floss down to the surface. Add fresh water up to the top of the neck. In a few hours (or overnight), there will be a rich collection of eels in the fresh water, but no noticeable mixing from the vinegar, below.

Collect the worms with a bulb baster or dropper. Remove the floss and squeeze dry. Pour enough vinegar back into the spare bottle to get good surface area again in the main culture bottle and loosely plug the top of the neck with the damp floss.

Another good point Wright mentioned is to use clear apple juice instead of apple pieces. It has the same effect but provides a cleaner culture.

© Copyright 1996-2000, Adrian R. Tappin - All rights reserved.
Updated December, 2000.