Nematodes look like tiny earth worms under the microscope and are quite common. They can be found in sand, debris, mud, and vegetation. Along wet areas of any body of water nematodes are likely living! They are not well understood, as there are a great many species and not many people have studied them. Taxonomic and ecological studies are lacking, and most information is from the early part of the 20th century. They are generally avoided because of their smallness, and thus making them hard to identify. There are a great many undescribed species, so if one would want to be the first to describe a nematode and get their name attached... here's your chance!
A good deal of the information available is written about the thousands of parasitic or predatory species of nematodes. This is because some of these nematodes affect us directly, and thereby brings the little 'worms' to light! A few reports of aquatic species exist, and some 1500 species have been reported world wide. But according to Pennak, it is probably a small percentage of the species in the world because they are diverse and range in areas from extremely cold climates such as Polar Ice, to Tropical climates. They also occur in deep water. Pennak reports "as of 1967" around 500 species have been recorded in Europe.
In our case, and in most nematodes, they do look like tiny earth worms, and they wiggle all the time. This wiggling allows them to work through whatever substrate they are living in to digest food, move about, and survive.
Aquaculturists use nematodes as a food for small larval organisms. Invertebrates and vertebrate carnivorous larval forms will eat nematodes. The size of a nematode compares to a brine shrimp nauplii, in being smaller in diameter, and several times longer. Larval fish, for example, will slurp them like spaghetti!
There is not much literature on nutritional value of nematodes. But they are used with good results. As with most feeds, none should be used as primary, but a part of a balanced diet (heard that often enough?)
In = commercial of nutritionally balance breakfast..
SETTING UP A CULTURE
Obtain a micro worm starter culture or wild collect them.
Using a plastic container = butter container, 4 oz tupperware, plastic shoe box, or something similar with a lid. It is recommended to put a few small holes in the lid to allow for breathing.
Use the following: Corn meal, oatmeal, baby cereal, bread, possibly any other grain you can get to a mushy consistency. Cooking the Corn meal or other grains, helps in making it mushy, (hominy grits might work too) but allow cooked feed to cool to room temperature before adding your nematodes or they will cook too. Baby Cereal doesn't need to be cooked. Nevertheless make the feed mushy... not too wet. A depth of 1/2 inch or less seems to work well. Sprinkle a pinch of bakers or brewers yeast on the top, and add your culture of nematodes. Within a few days the culture will start to spread out, and if the container is small, they will have taken over the whole surface in a day or so. The wiggling mass can be seen easily by raising the culture to a light at a little below eye level, and look at the light reflection on the culture surface. It should be writhing with worms!
After several days there will be so many worms they will be migrating up the sides of the container, even on the lid. They can be scraped off with a blade, or in the case of petri plates, the lid can be removed. Either way, then dip the blade or lid into the tank you wish to feed.. Or you can collect them into a bowl, by rinsing the lid/blade into the bowl. Then use an eye dropper to dispense the worms among your tanks. You can also harvest an entire culture by rinsing the culture into a sieve of 105 microns. Some of the feed will remain with the culture then, so you may want to use a larger sieve to catch the larger food particles, and saving the rinse off (which has the worms in it.) Then pour the rinse into a 105 micron screen to collect the worms.
Depending on the cultures, type of feed and temperatures the cultures can last up to several weeks, or go bad in a few days. If they start to smell, make new cultures. If activity stops on the surface, the culture has died... dump it.
You can add another sprinkle of yeast or mix in some new food if the culture appears to be declining in population. But making a new culture is almost as easy, and keeps any smell away. Keeping several new cultures starting up every few days, or once a week, depending on size of culture, will keep you in nematodes
Nematodes crawl up the sides of the container, they can be scraped of the sides, and fed directly to your larvae. Or you can use a 53 micron screen and rinse them of the meal juice they are in. Another method mentioned on our Bulletin Board by Doris can be found here: Click HERE and that thread has some interesting methods... Primarily using a stick for the little worms to crawl up, another is using something like filter floss, and rinsing the worms into a feeding bowl.
Nematodes make a great microscopic project for study!
As for feed, a good many fish will eat nematodes. Larval predatory organisms will eat them as a first food, and many adult 2" - 4" organisms will lap them up! I've read it's a good Cory food, and have reports from Betta (Siamese Fighting Fish) liking them.
I know Fat Head and Bannerfin Shiners like them, both the larvae minnows, and the adults. Using a large 6" tall x 12" wide x 24" high plastic storage bin, I was able to produce enought to fill 1/2 cupt of solid microworms. That harvest fed a great many adults, but it was a lot of work sorting the nematodes out of the food... still it worked, and they liked the worms bunches.
NEMATODE KIT DIRECTIONS
1. plastic container with lid
2. 1/4 OZ Oatmeal
3. Pinch of yeast
4. 100 ML Nematode (microworm) culture
5. Small meshed screen
1. Place oatmeal in container and wet until moist
2. Sprinkle tiny bit of Yeast (don't dump whole container, only need a tiny pinch)
3. Pour nematode culture over mixture
4. Poke a few holes through lid
5. Lay screen on top of container
6. Sandwhich screen between lid and container so it is taught. That will keep most bugs out
* Fresh-water Invertebrates of the United States, 3rd Ed. Protozoa to Mollusca. Robert W.
Pennak, John Wiley & Sons, Inc. pages 226 - 245.
* Unknown Author of Data Sheet I received
* Sachs Systems Aquaculture, ©2001 SSA Internet Publishing.
I've been looking for weeks for simple instructions and finally found them! Credit to jaykush for giving me the idea. Another stab to the corporate world.