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White Worm Culture (Enchytraeus albidus)

Paul Bachhausen [ CC BY-SA 3.0 de ]

Paul Bachhausen [CC BY-SA 3.0 de]

White Worms, Enchytraeus albidus, are commonly cultured by aquarists as a form of live fish food. The wiggling motion of the White Worms in water makes them irresistible to even the pickiest eaters. The various applicability and acceptance of White Worms has led to its widespread popularity. The first large scale production of Enchytraeus albidus was conducted by the former Soviet Union in the 1940’s. When the high nutritional value of White Worms were discovered, they were readily applied to enhance the increasing efforts in fish culturing. The relative high protein content made the White Worms worthy of a weekly production of up to 300 kilograms, mainly for use as juvenile sturgeon feed. Extensive studies on the nutritional value and cultivation of White Worms were conducted in the former Soviet Union during this period. Today, Enchytraeus albidus 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 expression is used to determine the effects of stressors on the environment. In the aquaculture industry, White Worms are commonly cultured in various sectors as fish feed. Large scale production is implied to integrate White Worms in formulated fish diets as a quality stock enhancement. Live forms of White Worm are commonly used for feeding smaller specimen or juvenile specimen via worm feeders. Besides fish, White Worms are also used to feed frogs, newts, reptiles, birds, and larger invertebrates.

Size

  • Length: 20 mm

  • Diameter: 1 mm

Nutritional Value

  • Protein: 70%

  • Lipids: 14.5%

  • Minerals: 5.5%

  • Carbohydrates: 10%

The use of White Worm for fish is very extensive. In fact, White Worms are one of the most valuable source of live food for fish and fish fry. The high protein content of White Worms enables peak growth rates for the most robust specimen. The particular size of White Worms makes them suitable for feeding fish that have outgrown smaller fish food such as Microworm, Baby Brine Shrimp, and Grindal Worms. The White Worms nutritional value consisting of high protein content makes them a great candidate for conditioning fish for breeding conditions. Spawning behavior of various species of fish can be triggered with the aid of White Worms. Since oligochaetes constitute a significant portion of food for fish in the wild, White Worms are a suitable food source to help mimic such natural environments.

 
 

White Worm Culture

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. In order to establish a successful White Worm culture, it is important to understand the necessary parameters. A White Worm culture care must not be neglected in order to constantly produce a high volume of fish food. Productive cultures can provide an abundance of high quality live fish food and routinely feed an entire fish room. White Worms must be maintained in a cool dark environment. The optimum White Worm culture temperature range is 12 – 21 °C. The higher range of the scale will result in faster maturity. However, production will slow down past 21 °C and the population will decrease with temperatures nearing 30 °C. White Worms will also die at temperatures nearing 0 °C. Wine chillers and small refrigerators can be used to effectively control the temperature of a culture year round. A variety of containers can be used to culture White Worms. One popular option for White Worm cultures are shallow wooden boxes. Wooden materials allow great moisture control and aeration at the same time. Wooden boxes can be constructed from pine or plywood. Alternative materials such as plastic and Styrofoam containers can be used as well as long as proper drainage and ventilation is provided. The ventilation holes should not exceed 2 mm in order to prevent contamination. An alternative method to small ventilation holes is to provide a larger opening with a sponge or cloth barrier. Since plastic and Styrofoam materials prevent air flow, it is necessary to routinely mix the culture media. Another important component of the culture container is the lid. The lid will prevent contamination of insects such as ants, beetles, flies, and mites. More importantly, the lid will block light as White Worm dislike any form of light. In order to satisfy this condition, transparent containers should be largely avoided unless the culture will remain in a dark environment. White Worm culture media should contain a high portion of organic matter. A pH of 6.8 – 7.2 is considered the optimum range, resulting in peak production levels. White Worms will not survive any acidic soils with pH levels below 5. In order to provide such conditions, there are various types of White Worm culture medium that can be used. The most common type of culture media for a White Worm culture is a soil based media. This consists of a 1:1 mixture of soil and peat moss. Potting soil with any addition of chemical fertilizers, sterilizers, or pesticides should be avoided as it will ultimately be passed onto the fish. Soil with a sandy or clay-like texture should be avoided as it will not provide proper aeration. 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. It is recommended to test the acidity of the mixture before application for best results. If the soil pH is acidic, the ratio of the peat moss can be reduced. The acidity can also be reduced by boiling the peat moss prior to adding it into the mixture. The latter method is more favorable as the ratio of the mixture will not be altered. While peat moss can slightly lower the pH of the culture media, it is highly beneficial to the culture as it provides superior moisture retention and control. If the soil in the culture media is from an outdoor source, it should be thoroughly searched for any contamination before adding it to the mixture. Small insects and larvae in the soil should be removed. Since outdoor soil often contains many small organisms such as mites that are difficult to detect to the naked eye, 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. A quick way to get rid of small mites in the soil is the microwave the soil. Purchasing the soil may be easier since soil from hardware stores and garden centers are treated prior to packaging. It is possible to culture White Worms with a soil-less culture media as well. Some of the options for a soil-less culture media include coconut fiber and sponge. The advantage of soil-less culture is the ease of maintaining cleanliness. However, a soil-less culture generally requires more attention and frequent maintenance since it lacks moisture retention. For White Worm cultures, the culture media should be maintained very moist at all times. Thus, the application of an inner surface cover is helpful. The surface cover can make harvesting the White Worms easier as well. Any flat material such as a thin piece of glass or plastic can be gently applied on the surface. The moisture retention is crucial since dry culture media will result in lower production rates and will ultimately result in the culture crashing. However, the moisture level must not be too wet either in order to maintain necessary air flow. A wet culture will produce an anaerobic environment which will also cause the culture to crash very quickly. Thus, a moist culture media with aeration must be maintained at all times. 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 for 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 of food can rot and cause a variety of issues. 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. Small frequent feedings are especially important for newly establishing cultures. The type of food can also determine the amounts of food that can be fed. Foods that are prone to rapid deterioration should be fed to only last a couple days. On the other hand, foods less prone to rotting such as dry food can be fed in larger quantity to last longer. The following is a list of food that can be fed to White Worms:

  • Bread Soaked in Milk/Yogurt

  • Oatmeal

  • Trout Feed

  • Dry Cat Food

  • Mash Potato

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. It is advisable to feed White Worms in a bare bottom tank. 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, one must be careful not to overfeed since fish will greedily feed on White Worms. Regular maintenance is crucial in order to maintain peak production levels in a White Worm culture. Without regular maintenance, a culture can quickly crash resulting from various issues. While examining a White Worm culture, it is important to pay special attention to the moisture level of the culture media. If the soil is too dry, the worms will burrow deep into the soil and ignore the food. When the soil is too wet, aeration of the culture media may be affected. In addition, it is important to regularly monitor the food level and any other irregularity. Some of the common issues with White Worm cultures are mites and mold. White Worm mites are very common especially in cultures with a soil based medium. While it can be difficult to completely eliminate mites in a soil based culture, mites population can be controlled effectively through a variety of methods. While manually removing individual mites can be a tedious task, clumps of mite populations can be removed while they are congregating on a food source. Another method of removing mites in White Worm culture is to temporarily flood the entire culture. Mites can be effectively removed from the culture as they float on the surface of the water. For a culture with excessive mites, re-culturing may be a better option. While removal of mites are necessary at times, the key is to control the population of mites by moisture control and preventing excessive food left over. In order to achieve a completely mite-free White Worm culture, a soil-less culture is more realistic. Another common issue with White Worm culture is mold. Similarly to mites, mold can be controlled by moisture control and preventing excessive food left over.

Posted on July 23, 2019 and filed under Journal, Guide.

Freshwater Fish vs Saltwater Fish

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While marine waters cover more than 70 percent of the earth’s surface, freshwater covers only 1 percent. Surprisingly however, 40 percent of the 28,000 species of fish dwell in fresh waters. This is a very high proportion of species density given the small area that the bodies of freshwater actually covers. This data indicates that there are approximately 1 species of fish for every 15 cubic kilometers of freshwater and 1 species of fish for every 100,000 cubic kilometers of marine waters. Constantly changing environments and ease of geographical separation of small bodies of water in freshwater habitat have resulted in a high degree of diversification of freshwater fish. The constantly changing environments have also forced freshwater fish to become more adaptive to their environment. In comparison, saltwater fish have been able to enjoy a relatively more stable environment in a larger ocean environment. Therefore, freshwater fish are generally more adaptable and hardier than saltwater fish.

Anatomy and Physiology

There are no significant anatomical differences that universally distinguishes freshwater fish and saltwater fish. The difference simply lies in the way that they regulate water and salts in their internal cells. Most freshwater fish and saltwater fish maintain a salt concentration in their blood of approximately 10 parts per thousand (ppt), or 10 grams of dissolved salt per liter of water. Since freshwater fish swim in water with approximately 0.5 ppt, the chloride cells in their gills are designed to pump sodium, calcium and chloride into the fish. On the other hand, since saltwater fish swim in water with approximately 35 ppt, the chloride cells in their gills are designed to pump salt out of the out of the fish. This process of controlling the flow of water across their body is called osmoregulation.

Freshwater Aquarium vs Saltwater Aquarium

When choosing between a freshwater aquarium setup and a saltwater aquarium setup, it is important to realize the difference in level of difficulty and level of care required. As mentioned, freshwater fish are hardier in general due to their adaptive nature. They are accepting of a wider range of water parameters as well. On the other hand, saltwater fish are generally more demanding of specific water parameters and required habitat. While market value of fish can vary depending on the season and distance from the coastal lines, marine fish are much more expensive compared to most freshwater species. Due to the additional equipment involved in a saltwater aquarium and the price tag of the fish itself, a saltwater aquarium setup in general is as twice as expensive as a freshwater aquarium setup.

 
 

Freshwater Setups

Due to the difference in cost and the level of care required, most novice aquarists decide to start the hobby with a freshwater aquarium. Just like saltwater fish, there are many colorful and attractive freshwater fish including cardinal tetras, fancy guppies, killifish, bettas, and cichlids, just to name a few. While generally not recommended for novice aquarists, discus fish is another very attractive freshwater fish with a variety of coloration. Even within the scope of freshwater aquariums, there is a great variety of tank setups available. Freshwater tropical community tanks are one of the most popular aquarium setups for both novice and advanced fishkeepers. While it is relatively inexpensive to set up and maintain, one can also appreciate a great variety of fish in a single aquarium. For community tanks however, it is important to understand the requirements of each species in the community in order to ensure compatibility. Since different species have different swimming patterns, combining top level swimmers, middle level swimmers, and bottom dwellers can be an attractive effect in a community tank. Basic components in a freshwater aquarium setup includes filtration, lighting, and heating. For freshwater aquariums without a heating mechanism, coldwater fish are most suitable. Coldwater fish includes goldfish and white cloud mountain minnows, among many other small river species. Another type of freshwater setup are fish bowls. Species of fish that can survive in bowls are very limited. While goldfish are commonly presented in small bowls, this is not very practical. Due to the high amount of waste output of carp species such as goldfish, a fish bowl without a filtration system will struggle to support the fish. Betta fish is a better candidate for a fish bowl since the developed labyrinth allows the fish to breathe atmospheric air. Finally, as a general rule of thumb it is advisable to provide at least 1 gallon of water for 1 inch of freshwater fish.

Saltwater Setups

There is a great abundance of colorful marine fish with striking patterns and body formations. While different species have varying requirements, saltwater aquarium setups can be categorized into three basic types. The most basic marine setup is the fish-only (FO) saltwater aquarium setup. This type of aquarium setup is well suited for novice saltwater fishkeepers due to its simplicity and the relative ease of care. FO aquariums are decorated with coral replicas instead of live rocks. Hardy marine fish such as Damselfish, as well as other tank-bred species, are great candidates for FO aquariums. Another type of marine tank setup is fish-only-with-live-rock (FOWLR) saltwater aquariums. Live rocks, which are pieces of mature coral reefs, allows colonization of a various marine life such as invertebrates and sponges. Since live rocks house an abundance of beneficial bacteria, it aids in filtration and maintaining desirable water parameters. Since live rock require specific acclimation techniques, lighting specifications, and supplements, FOWLR saltwater aquariums require a higher degree of care than FO saltwater aquariums. The most challenging type of aquarium, more so than FOWLR aquariums, are reef aquariums. In reef aquariums, the primary focus is placed on the corals, invertebrates, and anemones. While fish can be present in a reef aquarium, they are considered as an accessory of the entire setup. Reef aquariums require specific water parameters, lighting conditions, and water flow that must be maintained on a very regular basis. Thus, reef aquariums are generally reserved for the most advanced aquarists. Finally, as a general rule of thumb it is advisable to provide at least 5 -10 gallons of water for 1 inch of saltwater fish.

Brackish Setups

Brackish water aquariums lies between freshwater and saltwater aquariums. Difficulty in maintaining a brackish aquarium depends on the type of fish that is being housed. For novice fishkeepers, hardy fish such as Mollies are recommended for brackish aquariums. Just like a saltwater aquarium, a hydrometer is necessary in order to monitor the salinity in a brackish aquarium. Whenever there is a change in salinity, it should occur gradually in order to allow the fish to properly acclimate.

Posted on April 2, 2013 and filed under Guide, Journal.

Aquaculture in the U.S.

Seafood is a great food source for protein, vitamins, and minerals. This nutrient rich food source can provide us with essential omega-3 fatty acids not found in other foods. In fact, health experts are suggesting that we double our consumption of seafood for health benefits alone. Currently however, 85% of the seafood consumed in the U.S. is being imported from other countries. With the growth in global population, now reaching over 7 billion people, the demand for seafood continues to increase. In the meantime, wild harvest fisheries in many oceans worldwide are reaching a maximum sustainable yield. Thus, it is not difficult to predict a need for an efficient food production method such as aquaculture. With proper technique and sustainability in mind, aquaculture can be a very efficient and environmentally friendly means of producing quality food source.  Not surprisingly, aquaculture food production is in fact increasing at a steady rate in many countries. In Thailand, governmental and industrial outreach program have aided aquaculture to greatly succeed. However, in the U.S. the aquaculture industry have remained relatively stagnant with posed limitation on the industry in many states. While the U.S. exports the technology and equipment for aquaculture, local production remains scarce.

Posted on March 31, 2013 and filed under News, Journal.

What is the Plural Form of Fish?

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What is the plural form of fish? Some believe that the plural of fish is “fish,” while others claim that the plural of fish is “fishes.” In fact, they are both correct. However, while both “fish” and “fishes” can refer to the plural form of fish, they must be used appropriately. “Fish” can be used when referring to many fish of one species. For example, if a person is pointing at 10 goldfish he would say, “Look at those fish in the pond!” On the other hand, “fishes” is used when referring to many fish of multiple species. For example, if a person is pointing at 10 goldfish and 10 koi fish, he would say, “Look at those fishes in the pond!” So there you have it! The plural form of fish is “fish” AND “fishes.”

Posted on March 29, 2013 and filed under News, Journal.