Aquarium – Page 13 – Fish Laboratory Aquatics

White Worms, Enchytraeus albidus, are commonly cultured by aquarists as a form of fish food, more specifically live fish food. They can be fed to a wide variety of fish fry and smaller adult fish species. They are also fed to newts, salamanders, and some frogs. When the white worms are submerged underwater, they will wiggle rapidly, making them irresistible to even the pickiest feeders. Since they can be fed to a wide variety of aquatic organisms, they have gained widespread popularity among aquarium hobbyists and the aquaculture industry. White Worms in Aquaculture The first large scale production of Enchytraeus albidus was recorded in the 1940’s, in the former Soviet Union. Once it was discovered that white worms had a high protein content, they were produced in mass in order to enhance their efforts to grow sturgeons. Record indicates that they produced up to 300 kilograms of white worms on a weekly basis, mainly for use as juvenile feed. The optimal cultivation methods and nutritional value of the white worms were studied extensively during this period. Enchytraeus albidus, Paul Bachhausen [CC BY-SA 3.0] Today, white worms are still cultured in the aquaculture industry. They are used as live fish feed for many species of fish in their fry and juvenile stage. They are also produced at large scale in order to integrate them into formulated fish diets as a quality enhancer. In addition to the aquaculture industry, Enchytraeus albidus continue to be a subject of scientific studies as well. They are commonly used as a standard test organism in various biological and toxicological studies. Since white worms are sensitive to chemical contamination and other stress factors, their population level and gene expressions are used to determine the effects of stressors in the environment. White Worms as Aquarium Fish Food White worms can be a valuable source of live food for many aquarium fish. For most of the smaller fry, they will not be able to eat white worms as their first food. However, white worms are suitable after the fry outgrow microworms, baby brine shrimp, and Grindal Worms. Since white worms have a high nutritional content, it enables good growth rates and also help produce the most robust specimen. For smaller aquarium fish, white worms can be fed to them even after they reach adulthood. In fact, along with other live fish food such as gammarus, white worms are great for conditioning adult fish for breeding. Many fish breeders use white worms to help encourage their fish to breed in captivity. Since oligochaetes constitute a significant portion of food for many fish in the wild, white worms can be a great tool to help mimic such natural environments. White Worm Size Length: 20 mmDiameter: 1 mm White Worm Nutritional Value Protein: 70%Lipids: 14.5%Minerals: 5.5%Carbohydrates: 10% As industry experts realize the need to reduce their dependence of fish meal as a source of feed, researchers are once again taking an interest in alternatives such as white worms. New research from the New Hampshire Agricultural Experiment Station at the University of New Hampshire has found that live white worms are well-suited for the ornamental aquaculture industry and could be an emerging commercial industry for the region.- Lori Wright, NH Agricultural Experiment Station White Worm Culture Care White worm cultures can be a great source of quality food for your fish, but they are not exactly the easiest live cultures to care for. If you wish to harvest lots of worms, you will need the worms to not only survive, but thrive as well. In order to have the worms reproduce consistently at their maximum capacity, it is important to understand how to maintain certain parameters such as moisture level and soil pH. You will be able to harvest lots of worms, only if these requirements are met and maintained. Experienced breeders may be able to get large and consistent yields, but this will require some practice. First, let’s understand how to properly start and take care of your white worm culture. How to Start a White Worm Culture In order to start a white worm culture, you need a starter culture, culture container, culture media, and food. Once the materials are gathered, the white worm culture can be setup in the following simplified steps: Prepare culture media by sterilizing and adjusting pH of the soilEvenly spread 2-3 inches of soil in the culture containerAdd enough water to keep the soil moist, but not wetAdd the white worm starter cultureAdd a food source, such as bread covered in yogurtCover the culture with a non-airtight lidPlace the culture in a cool dark place Once the culture is setup, it should be monitored on regularly. Check to make sure that the culture is not drying out and there is enough food. Finding White Worm Cultures for Sale Where can you find a starter culture for sale? White worm cultures are often available for sale online from sellers on eBay, Amazon and Aquabid.com. Many breeders will keep a live culture year round and are willing to sell a portion of their culture. However, keep in mind that these worms are sensitive to hot temperature, so they may not ship very well in the hottest summer months. While white worms do prefer cooler temperatures, they may struggle in extreme cold during the winter as well. Local fish clubs may be a possible source of starter cultures. Unfortunately, they are rarely available in retail stores, including local fish stores. White Worm Culture Container A shallow container with a lid is required for white worms. If the container is airtight, you will need to create ventilation holes. A variety of containers can be used to culture white worms. Plastic shoe boxes are great for white worm cultures. They are just the right size for this purpose and they are inexpensive. In addition, it comes with a lid that is not airtight. This is important to keep a healthy aerobic environment for the white worms. If additional ventilation is required, you can easily drill small holes on the plastic lid. The ventilation holes should not exceed 2 mm in order to prevent flies and other insects from contaminating the culture. If the ventilation holes exceed 2mm, the opening can be covered with a sponge or cloth barrier. White worms dislike bright light. If the container allows light to pass through, it should be placed in a dark place. A cover can be placed over the container as well. Other containers that can be used for white worm cultures include wood boxes, Styrofoam containers, Tupperware containers and meal prep containers. As long as the container can hold the culture media, cover the culture, and keep the culture ventilated, it should be fine. However, containers that are very small should be avoided. If the culture is too small, it can dry out very quickly and crash the culture. White Worm Culture Media White worms can be cultured in a variety of different culture medium. Soil based cultures are the most common. The most important thing to consider for the culture medium is the soil pH and moisture retention. A pH of 6.8 – 7.2 is the optimal range. If the soil is outside of this range, the white worms may not be able to reproduce at its optimal speed. However, if the soil pH is below 5, white worms will simply not survive. pH can be measured by indicators or pH papers. Most tests of this form provide only broad results. The most accurate way to measure pH is by using digital pH meter. One of the best culture media for white worms can be created by mixing potting mix and peat moss at a 1:1 ratio. Peat moss hold the moisture very well. However, the peat moss is generally acidic with an approximate pH of 4.4. By mixing the potting mix, this will help balance the pH. If the pH is still too low even after mixing the potting mix, you can adjust it by adding more potting mix to the media. You can also boil the peat moss for 30 minutes to an hour to alter the pH. Boiling the culture media is a good way to sterilize as well. If possible, use organic soil with no harmful chemical additives. White worms are very sensitive to toxic substances. Even if the white worms did survive, keep in mind that you are growing these worms for fish food. Light soil with a mixture of coarse material is suitable as it will remain loose under moist conditions and provide adequate air flow. Soil for plant seedlings are specifically designed to maintain moisture and remain loose at the same time. Adding vermiculite or coconut coir mix can help aerate the soil. If you are collecting soil from the ground, sandy or clay-like soil should be avoided as it will not provide proper aeration. The soil should be thoroughly searched for any contamination as well. In order to avoid mites and other unwanted organisms competing with white worms, it is recommended to dry the soil out completely to get rid of them. In order to thoroughly dry out the soil, spread the soil out to a thin layer under strong sunlight for a few days. Boiling the soil in hot water is another good way to sterilize the soil. If you boil the soil, be sure to cool the soil before it comes in contact with the white worms. There are mixtures designed specifically for worms are well. Magic Worm Bedding can be used in white worm cultures to produce good yields. This mixture is made of a sphagnum peat moss base, and it hold up to twenty times it's own weight in moisture. Soil-Less White Worm Culture White worms can be grown in a soil-less culture by using a sponge as a culture media. The benefit of the soil-less culture is that it can allow more control and potentially reduce the risk of pests such as mites. The soil-less culture can be setup by adding a thin layer of water and placing the sponge on top of it. However, keep in mind that soil-less culture can be very difficult to maintain. Most sponge material do not retain moisture as well as a soil based culture. Therefore, the culture must be monitored more regularly to prevent drying out. Next, the waste that the worms constantly produce can alter the parameters and crash the culture very quickly. Since there are less buffers in a soil-less culture, the thin layer of water under the sponge needs to be changed very frequently. Soil-less white worm cultures can be more difficult to maintain than a soil based white worm culture. Therefore, it is not recommended if you are not experienced in culturing white worms. White Worm Culture Temperature White worms thrive in a cool dark environment. The optimum temperature for white worms are 55 – 68°F. The higher range of the scale will result in faster maturity. However, production will slow down past 69°F and the population will decrease with temperatures nearing 86°C. During the summertime, wine chillers and refrigerators can be used to control the culture temperature year round. Maintaining Moisture Since moisture is critical for the white worms, a cover can be very helpful. A clear material that can be lightly placed on top of the culture is ideal. Any flat material such as a thin piece of glass or plastic can be gently placed on the surface of the culture. The cover can make harvesting white worms easier later on as well. Regularly monitoring the moisture level of the culture is very important. If the culture surface gets too dry, the white worms will burrow deeper into the soil and stop feeding. This will significantly slow down reproduction. If the entire culture media gets too dry, the entire culture can crash. If the culture media is too wet, this will create an anaerobic environment which will also cause the culture to crash very quickly. The culture must remain moist, but aeration must be maintained as well. What to Feed White Worms White worms should be fed at the surface of the culture media for better monitoring of the culture condition and easier harvesting as well. By placing a flat piece of glass or plastic on the feeding surface, the food underneath will maintain the necessary moisture. This will allow the white worm to feed on it. The feeding amount should be relative to the size of the population in the culture. Overfeeding must be avoided as an excess food can rot and cause a variety of issues such as odor, mold, and pests. At the same time, white worm cultures should not be left without food for extended periods of time in order to maintain peak production level. Thus, the key is to provide small frequent feedings. This is especially important for newly establishing cultures. The following is a list of some of the food that can be fed to White Worms: Bread Soaked in YogurtOatmealTrout FeedDry Cat FoodMash Potato How Fast Do White Worms Reproduce? Enchytraeus albidus are hermaphroditic, with each individual specimen consisting of both male and female reproductive organs. Each specimen will produce a cocoon filled with eggs. While cocoon produced by younger specimen contain only about 10 eggs, mature specimen will produce cocoon with over 20 eggs. There have been reports of cocoons with up to 35 eggs. The egg filled cocoon hatches in 12 days after fertilization. Within the next 20 days, the newly hatched offspring will start to produce cocoons as well. An average White Worm will produce approximately 1000 eggs in their lifespan. In ideal conditions, White Worms can reproduce very rapidly and increase their population exponentially. How to Harvest White Worms In order to harvest white worms, lightly place a flat material on the surface of the culture. By placing a source of food under the flat material, white worms will gather in the area and climb on the surrounding flat surface. In order to harvest, lift the flat material and scrap the worms off the surface. Alternatively, if a mesh surface is placed on the surface, the white worms will gather in a mound on the top of the mesh where the food was placed. This method is highly efficient since it make it possible to collect a large amount of white worms without the soil. How to Feed Live White Worms to Your Fish It is advisable to feed white worms in a bare bottom or sand substrate tank. If the substrate is not fine, the white worms call fall in the cracks. Otherwise, feed slowly through a pipette or a worm feeder. White Worms will remain alive in underwater for several hours. As with all foods, uneaten White Worms should be removed in order to prevent water pollution. Lastly, be careful not to overfeed since fish will greedily feed on white worms. Mites in White Worm Culture As you keep an active white worm culture for some time, you may encounter the dreaded mites in your culture. There are ways to deal with a mite infestation, but it is best to prevent mites in the first place. Lets cover preventative measures first. Mite prevention starts at the very beginning. First, equipment and supplies used must be free of mites. This includes the soil media. By pouring boiling hot water, the majority of the risk can be mitigated. If this method is being used, be sure to properly cool the soil. After the culture is set up, maintain proper moisture level and do not overfeed. A healthy culture of worms should consume the food rather quickly. If conditions are not optimal, or there is simply too much food, this will increase the chance of mites and/or mold. If you mites do appear on the culture, keep in mind that once mites are introduced into a soil-based culture, it is nearly impossible to get rid of them completely. However, there are ways to suppress the population. First, try to manually remove any mites that you see to the best of your ability. The second method is to create a trap. Get a shallow cup, fill the cup with food grade diatomaceous earth. Place a small piece of food in the middle of the cup. As the mites are attracted to the food in the cup, it will get covered by the diatomaceous earth and be eliminated. This method will only work if the diatomaceous earth remain dry. Therefore, it will need to be replaced regularly. The third method is to flood the entire culture with water. Some of the mites will float on top of the water. Others will slowly come to the top. If this method is used, be sure to dry out the culture afterwards. White worms can only survive in water temporarily. If these method do not work, you should restart the culture. Collect a pure sample from the old culture. In order to make sure there are no mites contaminating the new culture, submerge the white worms in water first. Once you confirmed that there are no mites, the worms can be carefully extracted from the water with a pipette. Be sure to disinfect the surrounding area as well in order to prevent any mites from re-entering the new culture from outside. It is good practice to place the new culture in a new location for preventative measure as well. If mites become a recurring issue, you may wish to consider soil-less cultures. Re-Culturing White Worms Keep in mind that white worm cultures need to be re-cultured routinely, even if there are no mites. After a while, if you don’t change the culture media, it will eventually crash. The feeding and production of waste changes the pH of the culture media. Therefore, it is important to regularly re-culture. The size of the culture and the reproduction rate will determine how often white worms should be re-cultured. They can be re-cultured on a scheduled weekly cycle. They can also be re-cultured as needed. Once the soil starts to darken, it is a good sign to re-culture. New cultures may take a few days before it can be harvested. Therefore, if you wish to have a consistent source of feed, it is a good idea to maintain multiple cultures simultaneously.