The Joy of Nematodes part 2: Sex and the single eel!
by Humphry Axelbearing

Culturing Vinegar Eels:

Vinegar eels are one of my favorite nematodes (that is saying something since there are over 700 described species of nematodes) because of the ease of culture. They are so easy that before the days of pasteurization, they would frequently appear "spontaneously" in barrels of apple cider vinegar. To propagate vinegar eels, most people use a culture medium consisting of a 50% solution of cider vinegar and water but word is that they will apparently survive in anything from 10% to 100% vinegar. So get a bottle of the cheapest cider vinegar you can find that does not contain any sort of preservative. Find some kind of culture container (I prefer 2 liter soda bottles… the "duct-tape" of bio-culturing tools), fill it ~3&Mac218;4 full of your choice of vinegar solution and add a starter culture of vinegar eels. If you are starting the new culture from an established culture, shake the old one well before pouring a few ounces into your new culture container. Make sure you get some of the brown/gray mulm that is found in the bottom of the bottle, as it contains a fungi known as "mother of vinegar" which is a primary food source for the vinegar eels. Cover the bottle loosely (use a foam plug, or just set the bottle cap on top of the bottle) and place the bottle somewhere out of the way in the fishroom. My choice of locations depends only on making sure the bottle will not be easily knocked over, as the smell of vinegar can be somewhat unpleasant in large doses. Then sit back and have a beer! It will take about a month before you have enough eels to start harvesting, but once established the culture can be harvested for a long time. The best part is that once you establish the culture it needs no maintenance. And it is very rare for a vinegar eel culture to go bad… the worst I have ever seen is a culture that turned cloudy and all the eels died. In that case dump it out and start a new one. As always, I would advise keeping several cultures going so if you lose one you can restart from the others. The worst part about vinegar eels used to be the difficulty in harvesting the eels, but new methods have come to my attention recently that have simplified the process significantly. The first is what I will refer to as the "high-tech" method. It involves use of a disposable syringe filter and a big syringe. The filter will remove particles down to about 1 micron (one millionth of a meter) so it can easily separate the eels from the vinegar. Basically the technique is to fill the syringe with vinegar and eels, then force the solution thru the filter trapping the eels on one side. Then you simply backflush the filter with water into a container and feed with an eyedropper. The only drawback is getting ahold of the filters which are sold by scientific supply companies in bulkpacks of 50, or are available in small quantities from the WAKO live foods guys…The second method is the ultimate in low-tech. It uses a bottle with a long neck, and a wad of filter floss (or better yet open celled foam). Fill the bottle with vinegar and eels up to the base of the neck. Stuff a wad of floss into the neck of the bottle so that it is wedged down in the base of the bottle-neck and is saturated with vinegar but not submerged. Then if you pour water into the neck of the bottle, the eels will swim up into the water. Some eels will make it to the water very quickly, and if you wait an hour or so a lot more eels will follow. Next just pour off the water (or suck it up with a baster) into a cup. You can now feed with an eyedropper. If not eaten immediately, the eels will live for quite awhile in fry tanks. This is one significant advantage of vinegar eels compared to their cousins the microworms, which will barely live more than a day underwater.
Till next month…!

Keep your mops wet and your martinis dry!

The Hump