Originated by: Fisheries and Aquaculture Department
Title: Manual on the Production and Use of Live Food for Aquaculture...
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Friday, April 2, 2010
Culture Techniques of Moina :
The Ideal Daphnia for Feeding Freshwater Fish Fry1
R.W. Rottmann, J. Scott Graves, Craig Watson and Roy P.E. Yanong 2
Figure 1. Adult Moina.
There is considerable size variation between the genera. Moina are approximately half the maximum length of Daphnia. Adult Moina (700-1,000 µm) are longer than newly-hatched brine shrimp (500 µm) and approximately two to three times the length of adult rotifers. Young Moina (less than 400 µm), however, are approximately the same size or only slightly larger than adult rotifers and smaller than newly-hatched brine shrimp. In addition, brine shrimp die quickly in freshwater. As a result, Moina are ideally suited for feeding freshwater fish fry.
Newly-hatched fry of most freshwater fish species can ingest young Moina as their initial food. However, it should be noted that it can be difficult to grade Moina for size. It was found through trials at the UF/IFAS Tropical Aquaculture Laboratory that passing Moina through 500 micron mesh screening tends to fragment the animals to such an extent that they are no longer usable as live food. In aquaria, care must also be taken when determining feeding rates, as Moina can quickly grow too large to be eaten. If these larger Moina become too dense, their “hopping” movements can serve to harass and potentially damage fry.
Moina appear in high concentrations in pools, ponds, lakes, ditches, slow-moving streams and swamps where organic material is decomposing. They become especially abundant in temporary water bodies which provide them with suitable conditions for only a brief period.
Moina are generally quite tolerant of poor water quality. They live in water where the amount of dissolved oxygen varies from almost zero to supersaturation. Moina are particularly resistant to changes in the oxygen concentration and often reproduce in large quantities in water bodies strongly polluted with sewage. Species of Moina have been reported to play an important role in the stabilization of sewage in oxidation lagoons.
The ability to survive in oxygen-poor environments is due to their capacity to synthesize hemoglobin. Hemoglobin formation is dependent on the level of dissolved oxygen in the water. The production of hemoglobin may also be caused by high temperature and high population density.
Moina are resistant to extremes in temperature and easily withstand a daily variation of 41-88° F (5-31° C); their optimum temperature is 75-88° F (24-31° C). The high temperature tolerance of Moina is of great advantage for both the commercial fish farmers in the southern U.S. and hobbyists culturing live food at home.
Food Requirements
Life Cycles of Moina
Under adverse environmental conditions, males are produced and sexual reproduction occurs resulting in resting eggs (ephippia), similar to brine shrimp eggs. The stimuli for the switch from asexual to sexual reproduction in populations of Moina is an abrupt reduction in the food supply, resulting in an increase in resting egg production. However, it is advantageous to keep the population well fed and in the asexual mode of reproduction, since fewer progeny are produced with resting eggs.
A comparison of the production of Daphnia magna and Moina macrocopa cultures fertilized with yeast and ammonium nitrate, showed that the average daily yield of Moina (1.42-1.47 ounces/100 gallons; 106-110 g/m3) is three to four times the daily production of Daphnia (0.33-0.53 ounces/100 gallons; 25-40 g/m3). The daily yield of Moina cultures fed phytoplankton cultured on organic fertilizer have been reported to exceed 5 ounces/100 gallons (375 g/m3).
Nutritional Value of Moina
The nutritional content of Moina varies considerably depending on their age and the type of food they are receiving. Although variable, the protein content of Moina usually averages 50% of the dry weight. Adults normally have a higher fat content than juveniles. The total amount of fat per dry weight is 20-27% for adult females and 4-6% for juveniles.
The batch culture method of producing Moina uses a continuous series of cultures. Briefly, a new culture is started daily in a separate container using the procedures outlined below. When all the fungal, bacterial, and algal cells are consumed, usually about 5-10 days after inoculation, the Moina are completely harvested, and the culture is restarted. This method is particularly applicable when a specific quantity of Moina is needed each day because daily production is much more controlled.
Batch culture is also useful for maintaining pure cultures because there is less chance of the cultures becoming contaminated with competitors (e.g., protozoans, rotifers, copepods) or predators of fish larvae or fry (e.g., Hydra, back-swimmers, diving beetles, dragonfly larvae).
Cultures have been maintained in 10-gallon (38-L) aquaria. However, this volume usually only yields enough Moina for the hobbyist culturing live food. For larger scale and commercial operations, tanks or vats (concrete, stainless steel, plastic or fiberglass) and earthen ponds can be used. Wading pools, plastic sinks, old bathtubs, discarded refrigerator liners and cattle watering troughs also work well. Do not use unpainted metal containers unless they are stainless steel.
Water
The optimum water temperature for Moina is 75-88° F (24-31° C). Moina continue to thrive at temperatures in excess of 90° F (32° C) for short periods. However, low temperatures reduce production.
Aeration
Gentle aeration of the Moina pool oxygenates the water, keeps food particles in suspension and increases phytoplankton production; these result in an increase in the number of eggs per female, the proportion of egg-bearing females in the population, and the population density. A small trickle of fresh water into the culture container may also improve production of Moina. Only one or two aquarium air lines are required in culture containers up to 400 gallons (1.5 m3). Extremely small bubbles should be avoided as they can get trapped under the carapace, causing Moina to float at the surface, eventually killing them.
Feeding or Fertilizing
Yeast: 0.3-0.5 ounces (8.5-14.2 g) of baker's yeast.
Yeast and mineral fertilizer: 0.3-0.5 ounces (8.5-14.2 g) of yeast, and 0.5 ounces (14.2 g) of ammonium nitrate.
Alfalfa, bran and yeast: 1.5 ounces (42.5 g) of alfalfa pellets or meal, 1.5 ounces (42.5 g) of wheat or rice bran, and 0.3 ounces (8.5 g) of yeast.
Cow manure or sewage sludge, bran and yeast: 5 ounces (142 g) of dried manure or sewage sludge, 1.5 ounces (42.5 g) of wheat or rice bran, and 0.3 ounces (8.5 g) of yeast.
Cow manure or sewage sludge, cotton seed meal and yeast: Use 5 ounces (142 g) of dried manure or sewage sludge, 1.5 ounces (42.5 g) of cotton seed meal and 0.3 ounces (8.5 g) of yeast.
Horse or cow manure or sewage sludge: Combine 20 ounces (567 g) of dried manure or sewage sludge.
Chicken or hog manure: Combine 6 ounces (170 g) of dried manure.
Yeast and spirulina powder: 0.2 ounces (6 g) bakers yeast , 0.1 ounces (3 g) spirulina powder. Add this amount for the first two days, and then every other day until culture is harvested. Note: Add warm water to yeast and spirulina powder and let sit for 30 minutes. Stir and pour contents through a brine shrimp net into the Moina culture. The net will catch un-dissolved yeast and extend the life of the culture.
Organic fertilizers are usually preferred to mineral fertilizers because organic fertilizers provide bacterial and fungal cells and detritus as well as phytoplankton as food for the Moina. This variety of food items more completely meets their nutritional needs, resulting in maximum production. Mineral fertilizers may be used alone, however, they work better in earthen ponds than in tanks or vats.
Fresh manures are preferred because they are richer in organic matter and bacteria. However, some farm animals are given feed additives that control fly larvae in their manure and these may inhibit the production of Moina. Although not absolutely necessary, the manure is frequently dried before use. Commercially available organic fertilizers, such as dehydrated cow manure and sewage sludge, may be used for Moina cultures.
Although manure is widely used to culture Moina, yeast, alfalfa and bran are less objectionable to use and they work well. Activated yeast (baker's yeast) is readily available from wholesale food distributors in 2-pound (0.9-kg) bags. Bran and alfalfa meal or pellets can be purchased in 50-pound (22.7-kg) bags from livestock feed stores.
Coarse organic materials, such as manure, sewage sludge, hay, bran and oil seed meals, are usually suspended in the water column in mesh bags. Cheese cloth, burlap, muslin, nylon or other relatively loose weave fabrics may be used. Nylon and other synthetic fabrics, however, do not deteriorate in water as do cotton or burlap. For smaller culture containers, nylon stockings work well for this purpose, are inexpensive and readily available. The use of a bag prevents large particles from being a problem when the Moina are harvested and allows greater control of fertilization.
Over-feeding can quickly cause problems in water quality. Regardless of the type of media used, start with small amounts of feed or fertilizer added at frequent intervals and slowly increase the amount used as you gain experience. If fungus occurs in the culture container due to over-fertilization, the bag containing the organic material should be removed from the culture. If fungus persists in large quantities the culture should be discarded and restarted.
Excessively high pH (greater than 9.5), due to a heavy algae bloom and the resulting increase in the proportion of the toxic form of ammonia (un-ionized), may inhibit the production of Moina. The pH of the culture can be adjusted to 7-8 with vinegar (acetic acid).
Inoculating
Use pure live cultures to inoculate. Avoid using animals for inoculation from poor or declining cultures, cultures producing resting eggs, or cultures containing predators of fish larvae or fry. Inoculate with approximately 100 Moina/gallon (25/L). Although a culture can theoretically be started with a single female, always use an adequate number to develop a harvestable population quickly. If fewer are used, the population in the culture will increase more slowly, therefore, the initial quantity of fertilizer or food should be reduced to prevent over-feeding. A greater number used for inoculation reduces the time to harvesting and lessens the chance of contamination by competitors.
Cultures are usually inoculated 24 hours or more after fertilization. However, when yeast is used, Moina can be added to the culture after a few hours of aeration, assuming good water quality and proper temperature. This is because the yeast cells are immediately available to the Moina as food. The small amount of phytoplankton present in the water and digestive tract of the Moina used to inoculate the culture is usually sufficient to initiate a phytoplankton bloom.
Monitoring
The culture should be inspected daily to determine its health. The following observations should be made.
The health of the culture is determined by stirring the culture, removing 1 tablespoon (15 ml) of the culture, and examining the sample with a 8X- to 10X-hand lens or dissecting scope. Green or brown-red Moina with full intestinal tracts and active movement indicate a healthy culture. Pale Moina with empty digestive tracts or Moina producing resting eggs are indications of suboptimum environmental conditions or insufficient food.
The population density of Moina is determined by killing the Moina in a 1-teaspoon (3-5/ml) sample with a 70% alcohol solution and counting all Moina in a petri dish with a hand lens or dissecting scope. Cultures ready for harvest should contain 45-75 Moina in the 1-teaspoon sample (3-5/ml). With experience, population density can be estimated visually without the need for counts.
The food concentration in the culture water, when examined in a clear glass, should appear slightly cloudy and tea colored or green. Clear culture water is an indication of insufficient food. The cultures should be fed or fertilized with approximately 50-100% of the initial quantity whenever the transparency is greater than about 12-16 inches (0.3-0.4 m). This can be determined with a white plastic or metal lid approximately 4 inches (100 mm) in diameter, attached to the end of a yard stick. The depth of transparency is where the disk is just barely visible when lowered into the tank.
If predators of fish larvae or fry (e.g., Hydra, back-swimmers, diving beetles, dragonfly larvae) are observed, discard the culture and clean and disinfect the tank or pool to avoid contaminating other cultures.
Harvesting
Moina can be harvested by simply dipping out the required number with a brine shrimp net or re-usable coffee filter as they concentrate in "clouds" at the surface. Cultures may also be harvested by draining or siphoning the culture water into a plankton collector equipped with 50- to 150-µm mesh netting net suspended in a container of water. Turn off the aeration and allow the food particles to settle before harvesting. For semi-continuous culture, do not harvest more than 20-25% of the population each day, unless you are restarting the culture. Harvesting by draining the culture tank allows for a partial water exchange, improving water quality. Harvest only small quantities at a time and transfer the Moina to containers with fresh water to keep them alive.
The bottom sediments should be stirred up manually every day following harvest, thoroughly mixing the culture, to re-suspend food particles and prevent anaerobic conditions from developing.
Additional Points
Differences in size, brood production and optimum environmental conditions exist between different species and varieties of Moina. Adjustments will need to be made in the culture technique depending on the particular species or variety you wish to produce.
Additional surfaces in the culture tank may have a positive effect on the production of Moina. For Daphnia, a four-fold increase of surface area, in the form of plastic sheets, has been shown to result in a four-fold increase in the density, biomass and harvest. It is unknown whether this is the result of improved water quality due to nitrifying bacteria on the substrate, a change in the spatial distribution of the Daphnia or improved nutrition.
It may not always be possible to match Moina production to the food demand of the fish fry. Harvested Moina can be kept alive for several days in clean water in a refrigerator. They will resume normal activity when they are again warmed. The nutritional quality of the stored Moina will probably not be optimal because of the period of starvation, so the Moina should be enriched with algae and yeast before feeding them to fish.
Moina can be stored for long periods by freezing in low salinity water (7 ppt, 1.0046 density) or by freeze-drying. Both methods kill the Moina, so adequate circulation is required to keep them in suspension after thawing so they will be available to the fish fry. Frozen and freeze-dried Moina are not as nutritious as live animals and they are not as readily accepted by fish fry. Although freezing or freeze-drying does not significantly alter the nutritional content of Moina, nutrients do leach out rapidly into the water. Nearly all of the enzyme activity is lost within ten minutes after introduction in fresh water. After one hour, all of the free amino acids and many of the bound amino acids are lost.
Sources of Moina
Scott Graves or Robert Leonard
University of Florida
Tropical Aquaculture Laboratory
1408 14th ST SE
Ruskin, FL 33570
(813) 671-5230
Footnotes
1. This document is Circular 1054, one of a series from the Department of Fisheries and Aquatic Sciences, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. First published: May 1992. Revised: February 2003. Please visit the EDIS Web Site at http://edis.ifas.ufl.edu/.
R.W. Rottmann, J. Scott Graves, Craig Watson and Roy P.E. Yanong 2
Introduction
Daphnia are small freshwater cladoceran crustaceans commonly called “water fleas.” This common name is the result not only of their size, but their short, jerky hopping movement in water. The genera Daphnia and Moina are closely related. They occur throughout the world and are collectively known as daphnia.
Daphnia have a body consisting of a head and a trunk (Figure 1). The antennae are the main means of locomotion. Large compound eyes lie under the skin on the sides of the head. One of the major characteristics of daphnia is that the main part of the body, the trunk, is enclosed in an external skeleton (carapace). Periodically, they molt or shed their external shell. The brood pouch, where the eggs and embryos develop, is on the dorsal side of the female. In Daphnia, the brood pouch is completely closed, while Moina have an open pouch.
Daphnia have a body consisting of a head and a trunk (Figure 1). The antennae are the main means of locomotion. Large compound eyes lie under the skin on the sides of the head. One of the major characteristics of daphnia is that the main part of the body, the trunk, is enclosed in an external skeleton (carapace). Periodically, they molt or shed their external shell. The brood pouch, where the eggs and embryos develop, is on the dorsal side of the female. In Daphnia, the brood pouch is completely closed, while Moina have an open pouch.
Figure 1. Adult Moina.There is considerable size variation between the genera. Moina are approximately half the maximum length of Daphnia. Adult Moina (700-1,000 µm) are longer than newly-hatched brine shrimp (500 µm) and approximately two to three times the length of adult rotifers. Young Moina (less than 400 µm), however, are approximately the same size or only slightly larger than adult rotifers and smaller than newly-hatched brine shrimp. In addition, brine shrimp die quickly in freshwater. As a result, Moina are ideally suited for feeding freshwater fish fry.
Newly-hatched fry of most freshwater fish species can ingest young Moina as their initial food. However, it should be noted that it can be difficult to grade Moina for size. It was found through trials at the UF/IFAS Tropical Aquaculture Laboratory that passing Moina through 500 micron mesh screening tends to fragment the animals to such an extent that they are no longer usable as live food. In aquaria, care must also be taken when determining feeding rates, as Moina can quickly grow too large to be eaten. If these larger Moina become too dense, their “hopping” movements can serve to harass and potentially damage fry.
In Singapore, Moina micrura grown in ponds, fertilized with mostly chicken manure or, less frequently, with pig manure, are used as the sole food for fry of many ornamental tropical fish species, with a 95-99% survival rate to ¾ inch (20 mm) in length quite common. Unfortunately, there is very little information concerning practical mass culture methods of Moina, and the available information is in mimeograph documents, foreign journals or other scarce publications.
Physical and Chemical Requirements
Moina appear in high concentrations in pools, ponds, lakes, ditches, slow-moving streams and swamps where organic material is decomposing. They become especially abundant in temporary water bodies which provide them with suitable conditions for only a brief period.
Moina are generally quite tolerant of poor water quality. They live in water where the amount of dissolved oxygen varies from almost zero to supersaturation. Moina are particularly resistant to changes in the oxygen concentration and often reproduce in large quantities in water bodies strongly polluted with sewage. Species of Moina have been reported to play an important role in the stabilization of sewage in oxidation lagoons.
The ability to survive in oxygen-poor environments is due to their capacity to synthesize hemoglobin. Hemoglobin formation is dependent on the level of dissolved oxygen in the water. The production of hemoglobin may also be caused by high temperature and high population density.
Moina are resistant to extremes in temperature and easily withstand a daily variation of 41-88° F (5-31° C); their optimum temperature is 75-88° F (24-31° C). The high temperature tolerance of Moina is of great advantage for both the commercial fish farmers in the southern U.S. and hobbyists culturing live food at home.
Food Requirements
Moina feed on various groups of bacteria, yeast, phytoplankton and detritus (decaying organic matter). Bacterial and fungal cells rank high in food value. Populations of Moina grow most rapidly in the presence of adequate amounts of bacterial and yeast cells as well as phytoplankton. Moina are one of the few zooplankton which can utilize the blue-green algae Microcystis aeruginosa. Both plant and animal detritus may provide energy for the growth and reproduction of Moina. The food value of detritus depends on its origin and diminishes with the age of the detritus.
Life Cycles of Moina
The reproductive cycle of Moina has both a sexual and asexual phase. Normally, the population consists of all females that are reproducing asexually. Under optimum conditions, Moina reproduce at only 4-7 days of age, with a brood size of 4-22 per female. Broods are produced every 1.5-2.0 days, with most females producing 2-6 broods during their lifetime.
Under adverse environmental conditions, males are produced and sexual reproduction occurs resulting in resting eggs (ephippia), similar to brine shrimp eggs. The stimuli for the switch from asexual to sexual reproduction in populations of Moina is an abrupt reduction in the food supply, resulting in an increase in resting egg production. However, it is advantageous to keep the population well fed and in the asexual mode of reproduction, since fewer progeny are produced with resting eggs.
High population densities of Daphnia can result in a dramatic decrease in reproduction, but this is apparently not the case with Moina. The egg output of Daphnia magna drops sharply at a density as low as 95-115 mature individuals per gallon (25-30/L). The maximum sustained density in cultures of Daphnia reported is 1,900 individuals per gallon (500/L). Moina cultures, however, routinely reach densities of 19,000 individuals per gallon (5,000/L) and are, therefore, better adapted for intensive culture.
A comparison of the production of Daphnia magna and Moina macrocopa cultures fertilized with yeast and ammonium nitrate, showed that the average daily yield of Moina (1.42-1.47 ounces/100 gallons; 106-110 g/m3) is three to four times the daily production of Daphnia (0.33-0.53 ounces/100 gallons; 25-40 g/m3). The daily yield of Moina cultures fed phytoplankton cultured on organic fertilizer have been reported to exceed 5 ounces/100 gallons (375 g/m3).
Nutritional Value of Moina
The nutritional content of Moina varies considerably depending on their age and the type of food they are receiving. Although variable, the protein content of Moina usually averages 50% of the dry weight. Adults normally have a higher fat content than juveniles. The total amount of fat per dry weight is 20-27% for adult females and 4-6% for juveniles.
Procedure for Moina Culture
The batch culture method of producing Moina uses a continuous series of cultures. Briefly, a new culture is started daily in a separate container using the procedures outlined below. When all the fungal, bacterial, and algal cells are consumed, usually about 5-10 days after inoculation, the Moina are completely harvested, and the culture is restarted. This method is particularly applicable when a specific quantity of Moina is needed each day because daily production is much more controlled.
Batch culture is also useful for maintaining pure cultures because there is less chance of the cultures becoming contaminated with competitors (e.g., protozoans, rotifers, copepods) or predators of fish larvae or fry (e.g., Hydra, back-swimmers, diving beetles, dragonfly larvae).
Semi-continuous cultures can be maintained for two months or more by daily partial harvests of Moina, water changes and regular feeding, keeping the population in a state of rapid growth. Eventually, the Moina cultures will fail to respond to additional fertilization. When it is evident that they are not reproducing well, the Moina should be completely harvested and a new culture started.
Moina can be produced either in combination with their food or as separate cultures. Combined culture is the simplest, but production from separate cultures has been reported to be approximately higher.
For separate culture, the phytoplankton tank is positioned so that it can be drained into the Moina culture tank (Figure 2). Production from separate cultures has the disadvantage of requiring additional space for the cultivation of phytoplankton. However, there are advantages of separate culture of Moina and phytoplankton. The advantanges include less chance of contamination, a greater degree of control, and more consistent yield.
Note: Regardless of the culture method, always maintain several Moina cultures to ensure a supply in case of a die-off.
Note: Regardless of the culture method, always maintain several Moina cultures to ensure a supply in case of a die-off.
Cultures have been maintained in 10-gallon (38-L) aquaria. However, this volume usually only yields enough Moina for the hobbyist culturing live food. For larger scale and commercial operations, tanks or vats (concrete, stainless steel, plastic or fiberglass) and earthen ponds can be used. Wading pools, plastic sinks, old bathtubs, discarded refrigerator liners and cattle watering troughs also work well. Do not use unpainted metal containers unless they are stainless steel.
In these larger containers, water depth should be no greater than 3 feet (0.9 m). A maximum depth of 16-20 inches (0.4-0.5 m) is probably optimum. The shallow water depth allows good light penetration for photosynthesis by phytoplankton and provides a large surface to volume ratio for oxygen diffusion.
Diffuse light or shade over of the water surface of the Moina culture container is recommended. A greenhouse covered with shade cloth (50-80% light reduction) is ideal. Outdoor cultures should be protected from rain to help stabilize production and screened to prevent entry of predacious aquatic insects.
Containers to be used, whether aquaria, tanks, vats or ponds, need not be particularly clean. However, filamentous algae and predators of fish larvae or fry (e.g., Hydra, back-swimmers, diving beetles, dragonfly larvae) can be especially troublesome in Moina cultures. Tanks can be disinfected with a 30% solution of muriatic acid or by drying in sunlight. Earthen ponds should be drained and sun dried.
Diffuse light or shade over of the water surface of the Moina culture container is recommended. A greenhouse covered with shade cloth (50-80% light reduction) is ideal. Outdoor cultures should be protected from rain to help stabilize production and screened to prevent entry of predacious aquatic insects.
Containers to be used, whether aquaria, tanks, vats or ponds, need not be particularly clean. However, filamentous algae and predators of fish larvae or fry (e.g., Hydra, back-swimmers, diving beetles, dragonfly larvae) can be especially troublesome in Moina cultures. Tanks can be disinfected with a 30% solution of muriatic acid or by drying in sunlight. Earthen ponds should be drained and sun dried.
Water
Moina are extremely sensitive to pesticides, metals (e.g., copper and zinc, which may be prevalent in municipal or well water), detergents, bleaches and other toxic materials in the water supply. Ensure that toxins are not inadvertently introduced into the culture container. Well water should be aerated for at least two hours. Municipal water should be aerated for at least two days to neutralize the chlorine, or sodium thiosulfate or a commercially available chlorine neutralizer can be added to shorten this process. Natural spring water is ideal. Rain water is also excellent for Moina cultures if it is collected from an area that does not have excessive air pollution. Filtered lake or stream water may also be used.
The optimum water temperature for Moina is 75-88° F (24-31° C). Moina continue to thrive at temperatures in excess of 90° F (32° C) for short periods. However, low temperatures reduce production.
Aeration
Gentle aeration of the Moina pool oxygenates the water, keeps food particles in suspension and increases phytoplankton production; these result in an increase in the number of eggs per female, the proportion of egg-bearing females in the population, and the population density. A small trickle of fresh water into the culture container may also improve production of Moina. Only one or two aquarium air lines are required in culture containers up to 400 gallons (1.5 m3). Extremely small bubbles should be avoided as they can get trapped under the carapace, causing Moina to float at the surface, eventually killing them.
Feeding or Fertilizing
Listed below are some common fertilizer materials and application rates. Try several of these culture media to determine which one works best in your situation. The initial fertilization rates provided are only a starting point and will probably need to be adjusted depending on individual culture conditions.
The following quantity of fertilizer materials should be added initially for each 100 gallons (379 L) of water. Additional feed or fertilizer, approximately 50-100% of the initial amount, should be added about 5 days later.
The following quantity of fertilizer materials should be added initially for each 100 gallons (379 L) of water. Additional feed or fertilizer, approximately 50-100% of the initial amount, should be added about 5 days later.
Yeast: 0.3-0.5 ounces (8.5-14.2 g) of baker's yeast.
Yeast and mineral fertilizer: 0.3-0.5 ounces (8.5-14.2 g) of yeast, and 0.5 ounces (14.2 g) of ammonium nitrate.
Alfalfa, bran and yeast: 1.5 ounces (42.5 g) of alfalfa pellets or meal, 1.5 ounces (42.5 g) of wheat or rice bran, and 0.3 ounces (8.5 g) of yeast.
Cow manure or sewage sludge, bran and yeast: 5 ounces (142 g) of dried manure or sewage sludge, 1.5 ounces (42.5 g) of wheat or rice bran, and 0.3 ounces (8.5 g) of yeast.
Cow manure or sewage sludge, cotton seed meal and yeast: Use 5 ounces (142 g) of dried manure or sewage sludge, 1.5 ounces (42.5 g) of cotton seed meal and 0.3 ounces (8.5 g) of yeast.
Horse or cow manure or sewage sludge: Combine 20 ounces (567 g) of dried manure or sewage sludge.
Chicken or hog manure: Combine 6 ounces (170 g) of dried manure.
Yeast and spirulina powder: 0.2 ounces (6 g) bakers yeast , 0.1 ounces (3 g) spirulina powder. Add this amount for the first two days, and then every other day until culture is harvested. Note: Add warm water to yeast and spirulina powder and let sit for 30 minutes. Stir and pour contents through a brine shrimp net into the Moina culture. The net will catch un-dissolved yeast and extend the life of the culture.
Organic fertilizers are usually preferred to mineral fertilizers because organic fertilizers provide bacterial and fungal cells and detritus as well as phytoplankton as food for the Moina. This variety of food items more completely meets their nutritional needs, resulting in maximum production. Mineral fertilizers may be used alone, however, they work better in earthen ponds than in tanks or vats.
Fresh manures are preferred because they are richer in organic matter and bacteria. However, some farm animals are given feed additives that control fly larvae in their manure and these may inhibit the production of Moina. Although not absolutely necessary, the manure is frequently dried before use. Commercially available organic fertilizers, such as dehydrated cow manure and sewage sludge, may be used for Moina cultures.
Although manure is widely used to culture Moina, yeast, alfalfa and bran are less objectionable to use and they work well. Activated yeast (baker's yeast) is readily available from wholesale food distributors in 2-pound (0.9-kg) bags. Bran and alfalfa meal or pellets can be purchased in 50-pound (22.7-kg) bags from livestock feed stores.
Coarse organic materials, such as manure, sewage sludge, hay, bran and oil seed meals, are usually suspended in the water column in mesh bags. Cheese cloth, burlap, muslin, nylon or other relatively loose weave fabrics may be used. Nylon and other synthetic fabrics, however, do not deteriorate in water as do cotton or burlap. For smaller culture containers, nylon stockings work well for this purpose, are inexpensive and readily available. The use of a bag prevents large particles from being a problem when the Moina are harvested and allows greater control of fertilization.
Over-feeding can quickly cause problems in water quality. Regardless of the type of media used, start with small amounts of feed or fertilizer added at frequent intervals and slowly increase the amount used as you gain experience. If fungus occurs in the culture container due to over-fertilization, the bag containing the organic material should be removed from the culture. If fungus persists in large quantities the culture should be discarded and restarted.
Excessively high pH (greater than 9.5), due to a heavy algae bloom and the resulting increase in the proportion of the toxic form of ammonia (un-ionized), may inhibit the production of Moina. The pH of the culture can be adjusted to 7-8 with vinegar (acetic acid).
Inoculating
Use pure live cultures to inoculate. Avoid using animals for inoculation from poor or declining cultures, cultures producing resting eggs, or cultures containing predators of fish larvae or fry. Inoculate with approximately 100 Moina/gallon (25/L). Although a culture can theoretically be started with a single female, always use an adequate number to develop a harvestable population quickly. If fewer are used, the population in the culture will increase more slowly, therefore, the initial quantity of fertilizer or food should be reduced to prevent over-feeding. A greater number used for inoculation reduces the time to harvesting and lessens the chance of contamination by competitors.
Cultures are usually inoculated 24 hours or more after fertilization. However, when yeast is used, Moina can be added to the culture after a few hours of aeration, assuming good water quality and proper temperature. This is because the yeast cells are immediately available to the Moina as food. The small amount of phytoplankton present in the water and digestive tract of the Moina used to inoculate the culture is usually sufficient to initiate a phytoplankton bloom.
Monitoring
The culture should be inspected daily to determine its health. The following observations should be made.
The health of the culture is determined by stirring the culture, removing 1 tablespoon (15 ml) of the culture, and examining the sample with a 8X- to 10X-hand lens or dissecting scope. Green or brown-red Moina with full intestinal tracts and active movement indicate a healthy culture. Pale Moina with empty digestive tracts or Moina producing resting eggs are indications of suboptimum environmental conditions or insufficient food.
The population density of Moina is determined by killing the Moina in a 1-teaspoon (3-5/ml) sample with a 70% alcohol solution and counting all Moina in a petri dish with a hand lens or dissecting scope. Cultures ready for harvest should contain 45-75 Moina in the 1-teaspoon sample (3-5/ml). With experience, population density can be estimated visually without the need for counts.
The food concentration in the culture water, when examined in a clear glass, should appear slightly cloudy and tea colored or green. Clear culture water is an indication of insufficient food. The cultures should be fed or fertilized with approximately 50-100% of the initial quantity whenever the transparency is greater than about 12-16 inches (0.3-0.4 m). This can be determined with a white plastic or metal lid approximately 4 inches (100 mm) in diameter, attached to the end of a yard stick. The depth of transparency is where the disk is just barely visible when lowered into the tank.
If predators of fish larvae or fry (e.g., Hydra, back-swimmers, diving beetles, dragonfly larvae) are observed, discard the culture and clean and disinfect the tank or pool to avoid contaminating other cultures.
Harvesting
Moina can be harvested by simply dipping out the required number with a brine shrimp net or re-usable coffee filter as they concentrate in "clouds" at the surface. Cultures may also be harvested by draining or siphoning the culture water into a plankton collector equipped with 50- to 150-µm mesh netting net suspended in a container of water. Turn off the aeration and allow the food particles to settle before harvesting. For semi-continuous culture, do not harvest more than 20-25% of the population each day, unless you are restarting the culture. Harvesting by draining the culture tank allows for a partial water exchange, improving water quality. Harvest only small quantities at a time and transfer the Moina to containers with fresh water to keep them alive.
The bottom sediments should be stirred up manually every day following harvest, thoroughly mixing the culture, to re-suspend food particles and prevent anaerobic conditions from developing.
Additional Points
Differences in size, brood production and optimum environmental conditions exist between different species and varieties of Moina. Adjustments will need to be made in the culture technique depending on the particular species or variety you wish to produce.
Additional surfaces in the culture tank may have a positive effect on the production of Moina. For Daphnia, a four-fold increase of surface area, in the form of plastic sheets, has been shown to result in a four-fold increase in the density, biomass and harvest. It is unknown whether this is the result of improved water quality due to nitrifying bacteria on the substrate, a change in the spatial distribution of the Daphnia or improved nutrition.
It may not always be possible to match Moina production to the food demand of the fish fry. Harvested Moina can be kept alive for several days in clean water in a refrigerator. They will resume normal activity when they are again warmed. The nutritional quality of the stored Moina will probably not be optimal because of the period of starvation, so the Moina should be enriched with algae and yeast before feeding them to fish.
Moina can be stored for long periods by freezing in low salinity water (7 ppt, 1.0046 density) or by freeze-drying. Both methods kill the Moina, so adequate circulation is required to keep them in suspension after thawing so they will be available to the fish fry. Frozen and freeze-dried Moina are not as nutritious as live animals and they are not as readily accepted by fish fry. Although freezing or freeze-drying does not significantly alter the nutritional content of Moina, nutrients do leach out rapidly into the water. Nearly all of the enzyme activity is lost within ten minutes after introduction in fresh water. After one hour, all of the free amino acids and many of the bound amino acids are lost.
Sources of Moina
Scott Graves or Robert Leonard
University of Florida
Tropical Aquaculture Laboratory
1408 14th ST SE
Ruskin, FL 33570
(813) 671-5230
Footnotes
1. This document is Circular 1054, one of a series from the Department of Fisheries and Aquatic Sciences, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. First published: May 1992. Revised: February 2003. Please visit the EDIS Web Site at http://edis.ifas.ufl.edu/.
2. R.W. Rottmann, former Senior Biological Scientist, Department of Fisheries and Aquatic Sciences, Gainesville, and J. Scott Graves, Biological Scientist, Craig Watson, Director, and Roy P.E. Yanong, Assistant Professor, UF/IFAS Tropical Aquaculture Laboratory, Ruskin, FL 33570, Department of Fisheries and Aquatic Sciences, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL 32611.
The Institute of Food and Agricultural Sciences (IFAS) is an Equal Opportunity Institution authorized to provide research, educational information and other services only to individuals and institutions that function with non-discrimination with respect to race, creed, color, religion, age, disability, sex, sexual orientation, marital status, national origin, political opinions or affiliations. For more information on obtaining other extension publications, contact your county Cooperative Extension service. U.S. Department of Agriculture, Cooperative Extension Service, University of Florida, IFAS, Florida A. & M. University Cooperative Extension Program, and Boards of County Commissioners Cooperating. Millie Ferrer-Chancy, Interim Dean.
The Institute of Food and Agricultural Sciences (IFAS) is an Equal Opportunity Institution authorized to provide research, educational information and other services only to individuals and institutions that function with non-discrimination with respect to race, creed, color, religion, age, disability, sex, sexual orientation, marital status, national origin, political opinions or affiliations. For more information on obtaining other extension publications, contact your county Cooperative Extension service. U.S. Department of Agriculture, Cooperative Extension Service, University of Florida, IFAS, Florida A. & M. University Cooperative Extension Program, and Boards of County Commissioners Cooperating. Millie Ferrer-Chancy, Interim Dean.
PENYEDIAAN MAKANAN ANAK BENIH OLEH EN. JOHARI PUSAT PERIKANAN BUKIT TINGGI , KARAK, PAHANG.
•1.0 Pendahuluan.
•Merupakan makanan asasi bagi rega & benih.
•Makanan utama bagi rega yg berumur 4 hari
• ( mulut mula terbuka ) – mencapai umur 1 bulan atau sehingga mampu memakan makanan lain.
•Sangat penting dalam pembenihan ikan air tawar.
•Tanpa makanan hidup, benih yg banyak tidak dapat dihasilkan.
•Merupakan kunci kejayaan dalam pengeluaran benih ikan air tawar.
•Terdiri dari air hijau, moina, cacing dan artemia.
•Makanan hidup ini boleh di ternak di dalam kolam tanah, kolam simen, tangki kanvas dan tangki gentian kaca.
•Merupakan makanan asasi bagi rega & benih.
•Makanan utama bagi rega yg berumur 4 hari
• ( mulut mula terbuka ) – mencapai umur 1 bulan atau sehingga mampu memakan makanan lain.
•Sangat penting dalam pembenihan ikan air tawar.
•Tanpa makanan hidup, benih yg banyak tidak dapat dihasilkan.
•Merupakan kunci kejayaan dalam pengeluaran benih ikan air tawar.
•Terdiri dari air hijau, moina, cacing dan artemia.
•Makanan hidup ini boleh di ternak di dalam kolam tanah, kolam simen, tangki kanvas dan tangki gentian kaca.
•2.0 Jenis-jenis makanan hidup.
•2.1 Air Hijau.
•Air yg mengandungi fitoplankton – organisma satu sel yg terdiri dari beberapa spesies yg mempunyai klorofil a yg menjalankan proses fotosintesis bagi menghasilkan makanan untuk pertumbuhan sel & membiak untuk membentuk koloni atau populasi yang banyak.
•Koloni dihasilkan melalui pembiakan asexual iaitu pembiakan secara pembahagian sel ( binary fision ).
•Mengandungi protin yg tinggi & sangat berguna kepada benih yang diasuh.
•Spesies utama yang sangat berguna ialah Chorella sp.
•Spesies ini mengandungi protien yg tinggi dan asid amino yang diperlukan oleh benih untuk membesar.
•Spesies ini Cuma boleh dilihat di bawah mikroskop.
•Kehadiran spesies ini dalam air dapat ditentukan melalui warna air.
•Air kolam yg berwarna hijau menunjukkan kehadiran spesies ini.
•Selain digunakan untuk asuhan benih ikan, spesies ini telah digunakan sebagai makanan kesihatan oleh manusia.
•2.2 Moina.
•Sejenis zooplankton dalam kelas Krustasia.
•Spesies ini mudah didapati di kolam-kolam oksidasi bahan kumbahan domestik.
•Pd masa ini ramai penternak ikan hiasan mendapatkan bekalan moina dari kolam oksidasi.
•Moina yg dipungut dari kolam oksidasi tidak sesuai untuk makanan benih.
•Mengandungi banyak bakteria terutamanya E. coli & bakteria lain yg merbahaya kpd kesihatan manusia.
•Moina boleh diternak di dalam tangki atau kolam tanah.
•2.1 Air Hijau.
•Air yg mengandungi fitoplankton – organisma satu sel yg terdiri dari beberapa spesies yg mempunyai klorofil a yg menjalankan proses fotosintesis bagi menghasilkan makanan untuk pertumbuhan sel & membiak untuk membentuk koloni atau populasi yang banyak.
•Koloni dihasilkan melalui pembiakan asexual iaitu pembiakan secara pembahagian sel ( binary fision ).
•Mengandungi protin yg tinggi & sangat berguna kepada benih yang diasuh.
•Spesies utama yang sangat berguna ialah Chorella sp.
•Spesies ini mengandungi protien yg tinggi dan asid amino yang diperlukan oleh benih untuk membesar.
•Spesies ini Cuma boleh dilihat di bawah mikroskop.
•Kehadiran spesies ini dalam air dapat ditentukan melalui warna air.
•Air kolam yg berwarna hijau menunjukkan kehadiran spesies ini.
•Selain digunakan untuk asuhan benih ikan, spesies ini telah digunakan sebagai makanan kesihatan oleh manusia.
•2.2 Moina.
•Sejenis zooplankton dalam kelas Krustasia.
•Spesies ini mudah didapati di kolam-kolam oksidasi bahan kumbahan domestik.
•Pd masa ini ramai penternak ikan hiasan mendapatkan bekalan moina dari kolam oksidasi.
•Moina yg dipungut dari kolam oksidasi tidak sesuai untuk makanan benih.
•Mengandungi banyak bakteria terutamanya E. coli & bakteria lain yg merbahaya kpd kesihatan manusia.
•Moina boleh diternak di dalam tangki atau kolam tanah.
•Ternakan dalam tangki dipilih kerana hasil yg diperolehi adalah satu spesies sahaja ( pure culture ).
•Pengurusan ternakan adalah mudah.
•Hasil yg diperolehi adalah banyak, bersih dan tidak membawa penyakit kpd benih yg diasuh.
•Jika ternakan dalam kolam tanah dijalankan, hasil yg diperolehi adalah pelbagai spesies dan bercampur aduk dengan serangga dan cacing.
•Keadaan ini sukar dikendalikan dan banyak kerja pengasingan perlu dilakukan.
•Pengurusan ternakan adalah mudah.
•Hasil yg diperolehi adalah banyak, bersih dan tidak membawa penyakit kpd benih yg diasuh.
•Jika ternakan dalam kolam tanah dijalankan, hasil yg diperolehi adalah pelbagai spesies dan bercampur aduk dengan serangga dan cacing.
•Keadaan ini sukar dikendalikan dan banyak kerja pengasingan perlu dilakukan.
•2.3 Cacing.
•Ada dua jenis iaitu
•Cacing tubefax( tubefax worm ).
•Cacing darah ( blood worm ).
•Cacing tubefax boleh didapati di sungai atau longkang yg tercemar dari kumbahan domestik, ladang ternakan haiwan dan kilang yg berasaskan pertanian. eg kilang ubi kayu.
•Cacing dari kawasan ini tidak sesuai diberi kpd benih ikan kerana cacing ini membawa bahan toksid dan bakteria dalam badannya.
•Boleh mengancam kesihatan benih ikan.
•Cacing darah adalah merupakan larvae kpd sejenis lalat liar.
•Lalat ini akan bertelur dipermukaan air.
•Telur akan menetas dan larvae berkembang di dasar.
•Cacing ini membuat sarang dan tinggal di dalamnya sehingga cukup sifat dan terbang.
•Cacing ini boleh diternak di dalam tangki.
•Ada dua jenis iaitu
•Cacing tubefax( tubefax worm ).
•Cacing darah ( blood worm ).
•Cacing tubefax boleh didapati di sungai atau longkang yg tercemar dari kumbahan domestik, ladang ternakan haiwan dan kilang yg berasaskan pertanian. eg kilang ubi kayu.
•Cacing dari kawasan ini tidak sesuai diberi kpd benih ikan kerana cacing ini membawa bahan toksid dan bakteria dalam badannya.
•Boleh mengancam kesihatan benih ikan.
•Cacing darah adalah merupakan larvae kpd sejenis lalat liar.
•Lalat ini akan bertelur dipermukaan air.
•Telur akan menetas dan larvae berkembang di dasar.
•Cacing ini membuat sarang dan tinggal di dalamnya sehingga cukup sifat dan terbang.
•Cacing ini boleh diternak di dalam tangki.
•2.4 Artemia.
•Sejenis zooplankton dalam kelas krustasia.
•Hidup dalam air masin terutamanya di dalam tasek garam yang terdapat di Amerika.
•Dalam tasek yg normal, artemia akan hidup seperti zooplankton yg lain.
•Bila suhu meningkat & air tersejat, kemasinan air akan meningkat.
•Keadaan ini tidak disukai oleh artemia & jika keadaan berlarutan ia akan mati.
•Demi untuk menjamin kesinambungan generasinya, maka ia memaskanya dirinya berada dalam fasa dorman.
•Menghasilkan sista yg kebal & tahan terhadap perubahan alam sekitarnya.
•Dalam fasa ini artemia akan melalui fasa rehat di dalam sista.
•Sista akan terapung di atas permukaan air tasek garam.
•Sista akan dikutip dengan menggunakan penyauk halus, dibersihkan, dinyah kuman sebelum di pek dalam bekas dan di dagangkan.
•Apabia sista ini berada di dalam air dan keadaan telah berubah dan sesuai untuk artemia, maka sista akan menetas dan menghasilkan artemia yang baru.
•Sejenis zooplankton dalam kelas krustasia.
•Hidup dalam air masin terutamanya di dalam tasek garam yang terdapat di Amerika.
•Dalam tasek yg normal, artemia akan hidup seperti zooplankton yg lain.
•Bila suhu meningkat & air tersejat, kemasinan air akan meningkat.
•Keadaan ini tidak disukai oleh artemia & jika keadaan berlarutan ia akan mati.
•Demi untuk menjamin kesinambungan generasinya, maka ia memaskanya dirinya berada dalam fasa dorman.
•Menghasilkan sista yg kebal & tahan terhadap perubahan alam sekitarnya.
•Dalam fasa ini artemia akan melalui fasa rehat di dalam sista.
•Sista akan terapung di atas permukaan air tasek garam.
•Sista akan dikutip dengan menggunakan penyauk halus, dibersihkan, dinyah kuman sebelum di pek dalam bekas dan di dagangkan.
•Apabia sista ini berada di dalam air dan keadaan telah berubah dan sesuai untuk artemia, maka sista akan menetas dan menghasilkan artemia yang baru.
•3.0 Ternakan makanan hidup.
•3.1 Air Hijau.
•Jenis-jenis tangki ternakan.
•Tangki fibreglass.
•Berbentuk segiempat bujur.
•Saiz antara 1.0m x2.0m x 1.0 m hingga 2.0m x 4.0m x 1.0 m
•Dalam air – 60 cm
•ii. Kolam konkrit.
•Berbentuk segiempat bujur.
•Saiz antara 1.0 m x 3.0m x 1.0m hingga 5.0m x 10.0cm x 1.0 m.
•Dalam air – 60 cm
•b. Penyediaan tangki ternakan.
•Pembersihan tangki/kolam.
•Keringkan air kolam.
•Bersihkan kolam/tangki dari lumut & sisa baja.
•Bilas dengan air bersih.
•Jemur tangki/kolam selama 2 – 3 jam.
•ii. Membaja kolam/tangki.
•3 jenis baja – ami-ami, urea & triplesuoerfosfat.
•Masukkan ami-ami pd kadar 0.5 kg/tan air, urea 0.1 kg/tan air dan triplesuperfosfat pd kadar 0.1 kg/tan air.
•Larutkan & kacau sehingga sebati.
•Pembersihan tangki/kolam.
•Keringkan air kolam.
•Bersihkan kolam/tangki dari lumut & sisa baja.
•Bilas dengan air bersih.
•Jemur tangki/kolam selama 2 – 3 jam.
•ii. Membaja kolam/tangki.
•3 jenis baja – ami-ami, urea & triplesuoerfosfat.
•Masukkan ami-ami pd kadar 0.5 kg/tan air, urea 0.1 kg/tan air dan triplesuperfosfat pd kadar 0.1 kg/tan air.
•Larutkan & kacau sehingga sebati.
•iii. Memasukkan air.
•Masukkan air sedalam 30 cm.
•Kacau sehingga rata.
•Kolam/tangki kaya dengan nutrien yang diperlukan oleh fitoplankton.
•iv. Inokulasi benih air hijau.
•Pd hari berikutnya masukkan air hijau sebanyak 2 tan dgn memindahkan air dari kolam sediada.
•Tambahkan air bersih sehingga paras 60 cm.
•Pd hari ke 3 – 7 air akan menjadi hijau & air ini boleh digunakan untuk mengasuh benih ikan.
•3.2 Moina.
•Masukkan air sedalam 30 cm.
•Kacau sehingga rata.
•Kolam/tangki kaya dengan nutrien yang diperlukan oleh fitoplankton.
•iv. Inokulasi benih air hijau.
•Pd hari berikutnya masukkan air hijau sebanyak 2 tan dgn memindahkan air dari kolam sediada.
•Tambahkan air bersih sehingga paras 60 cm.
•Pd hari ke 3 – 7 air akan menjadi hijau & air ini boleh digunakan untuk mengasuh benih ikan.
•3.2 Moina.
•Jenis-jenis tangki ternakan.
•Tangki fibreglass.
•Berbentuk segiempat bujur.
•Saiz : 1.0 m x 2.0 m x 1.0 m hingga 2.0 m x 3.0 m x 1.0 m .
•Dalam air 60 cm.
•ii. Kolam Konkrit.
•Berbentuk segiempat bujur.
•Saiz : 1.0 m x 2.0 m x 1.0 m hingga 5.0 m x 10.0 m x 1.0 m
•Dalam air adalah 60 cm.
•b. Penyediaan tangki ternakan.
•Pembersihan tangki/kolam.
•Keringkan air kolam/tangki.
•Bersihkan tangki dari lumut & sisa baja.
•Bilas dengan air bersih.
•Jemur tangki selama 2 – 3 hari.
•ii. Memindahkan air hijau ke tangki/kolam.
•Masukkan air bersih sehingga ke paras 30 cm.
•Pindahkan air hijau dari tangki air hijau ke kolam ternakan sehingga ke paras 60 cm.
•Berikan pengudaraan.
•Densiti air hijau akan meningkat.
•iii. Inokulasi benih moina.
•Tangkap moina dgn sauk halus sebanyak 1.0 kg
•Pindahkan ke dalam tangki ternakan.
•Biarkan moina berkembang biak selama 4 hari.
•Moina memakan fitoplankton.
•Moina membiak dengan cara bertelur.
•Telur menetas menghasilkan larvae.
•Larvae akan membesar dgn memakan fitoplankton.
•Kitar hidup moina pendek antara 7 – 10 hari.
•Selepas 10 hari moina akan mati & generasi baru akan berkembang biak.
•Tangkap moina dgn sauk halus sebanyak 1.0 kg
•Pindahkan ke dalam tangki ternakan.
•Biarkan moina berkembang biak selama 4 hari.
•Moina memakan fitoplankton.
•Moina membiak dengan cara bertelur.
•Telur menetas menghasilkan larvae.
•Larvae akan membesar dgn memakan fitoplankton.
•Kitar hidup moina pendek antara 7 – 10 hari.
•Selepas 10 hari moina akan mati & generasi baru akan berkembang biak.
•Jumlah populasi yg terbentuk adalah bergantung kpd kekerapan pembiakan & peneluran, bekalan fitoplankton dan mutu air.
•Kandungan oksigen, pH & nitrat perlu sesuai untuk mempercepatkan perkembangan dan penghasilan moina.
•Sekiranya pd hari kedua warna air bertukar dari hijau kpd cokelat atau jernih, tambahkan air hijau supaya makanan sentiasa mencukupi.
•Ulangi proses ini hingga hari ke empat ternakan dijalankan.
•Moina akan sentiasa membiak setiap hari jika mutu air berada pada paras yang sesuai.
•Kandungan oksigen, pH & nitrat perlu sesuai untuk mempercepatkan perkembangan dan penghasilan moina.
•Sekiranya pd hari kedua warna air bertukar dari hijau kpd cokelat atau jernih, tambahkan air hijau supaya makanan sentiasa mencukupi.
•Ulangi proses ini hingga hari ke empat ternakan dijalankan.
•Moina akan sentiasa membiak setiap hari jika mutu air berada pada paras yang sesuai.
•c. Kutipan hasil.
•Selepas 4 hari benih moina diinokulasi ke dalam tangki ternakan, ia berkembang biak & menghasilkan moina yang banyak.
•Jika benih 1.0 kg dilepaskan ke dalam kolam ternakan hasil yg diperolehi ialah 4.5 – 5.5 kg.
•Jumlah ini boleh ditingkatkan dgn menambah volume air ternakan, meningkatkan DO, meningkatkan jumlah makanan dan pengawasan mutu air yg baik.
•Kutipan hasil dijalankan pada waktu pagi sebelum jam 10.00 pagi.
•Masa utk menjalankan kerja-kerja kutipan adalah
•Selepas 4 hari benih moina diinokulasi ke dalam tangki ternakan, ia berkembang biak & menghasilkan moina yang banyak.
•Jika benih 1.0 kg dilepaskan ke dalam kolam ternakan hasil yg diperolehi ialah 4.5 – 5.5 kg.
•Jumlah ini boleh ditingkatkan dgn menambah volume air ternakan, meningkatkan DO, meningkatkan jumlah makanan dan pengawasan mutu air yg baik.
•Kutipan hasil dijalankan pada waktu pagi sebelum jam 10.00 pagi.
•Masa utk menjalankan kerja-kerja kutipan adalah
•Bergantung kpd densiti, saiz net dan cara kutipan hasil dijalankan.
•Sebagai contoh untuk memungut hasil sebanyak 5.0 kg mengambil masa 5 jam.
•Kutipan hasil dijalankan dgn menggunakan net halus yg direkabentuk khas untuk menangkap moina.
•Saiz net ialah 45 cm x 120 cm dgn saiz mata 0.1 mm.
•Bhg mulut net dipasang pada paip saluran air keluar.
•Buka pintu air & biarkan air mengalir melalui net.
•Moina akan terperangkap di dalam net.
•d. Pengendalian hasil lepas tuai.
•Diberi terus kepada rega.
•Moina yg dipungut boleh diberi terus kpd rega.
•Caranya mudah, ambil moina dan masukkan ke dalam tangki asuhan benih.
•Moina akan berenang sambil memakan plankton.
•Rega yg diasuh akan memakan moina.
•Moina yg tidak habis dimakan akan terus hidup dan membiak.
•Penternak akan menambah moina.
•Proses ini akan berulangan sehingga benih mencapai saiz pasaran & dijual.
•ii. Moina segar.
•Moina boleh disimpan dalam bekas yg mengandungi air dan pengudaraan.
•Boleh disimpan untuk satu jangkamasa tertentu sahaja kerana faktor kitar hidup.
•Tujuannya ialah utk membolehkan benih ikan mendapat moina yang segar sepanjang masa.
•Melalui cara ini moina tidak dapat disimpan dengan lebih lama lagi akibat faktor kitar hidup, bekalan makanan yang terhad bagi moina.
•Sebagai contoh untuk memungut hasil sebanyak 5.0 kg mengambil masa 5 jam.
•Kutipan hasil dijalankan dgn menggunakan net halus yg direkabentuk khas untuk menangkap moina.
•Saiz net ialah 45 cm x 120 cm dgn saiz mata 0.1 mm.
•Bhg mulut net dipasang pada paip saluran air keluar.
•Buka pintu air & biarkan air mengalir melalui net.
•Moina akan terperangkap di dalam net.
•d. Pengendalian hasil lepas tuai.
•Diberi terus kepada rega.
•Moina yg dipungut boleh diberi terus kpd rega.
•Caranya mudah, ambil moina dan masukkan ke dalam tangki asuhan benih.
•Moina akan berenang sambil memakan plankton.
•Rega yg diasuh akan memakan moina.
•Moina yg tidak habis dimakan akan terus hidup dan membiak.
•Penternak akan menambah moina.
•Proses ini akan berulangan sehingga benih mencapai saiz pasaran & dijual.
•ii. Moina segar.
•Moina boleh disimpan dalam bekas yg mengandungi air dan pengudaraan.
•Boleh disimpan untuk satu jangkamasa tertentu sahaja kerana faktor kitar hidup.
•Tujuannya ialah utk membolehkan benih ikan mendapat moina yang segar sepanjang masa.
•Melalui cara ini moina tidak dapat disimpan dengan lebih lama lagi akibat faktor kitar hidup, bekalan makanan yang terhad bagi moina.
iii. Moina beku.
•Moina boleh disejukbeku di dlm refrigerator.
•Masukkan moina ke dlm bekas atau beg plastik.
•Bekukan dlm refrigerator.
•Dgn cara ini moina boleh disimpan lebih lama sebagai moina beku.
•Moina ini boleh dijual atau digunakan pada bila-bila masa sahaja.
•Menyimpan moina cara ini penting agar bekalan moina tidak terputus.
•Cara untuk memberi moina beku kpd benih adalah mudah.
•Keluarkan moina dari bekas.
•Moina boleh disejukbeku di dlm refrigerator.
•Masukkan moina ke dlm bekas atau beg plastik.
•Bekukan dlm refrigerator.
•Dgn cara ini moina boleh disimpan lebih lama sebagai moina beku.
•Moina ini boleh dijual atau digunakan pada bila-bila masa sahaja.
•Menyimpan moina cara ini penting agar bekalan moina tidak terputus.
•Cara untuk memberi moina beku kpd benih adalah mudah.
•Keluarkan moina dari bekas.
•Masukkan moina itu ke dalam kolam.
•Bungkah moina itu akan terapung.
•Benih akan mengerumuni dan memakan moina yang terpisah akibat pencairan moina beku.
•Masa yang diambil untuk memakan moina seberat 0.5 kg oleh 20,000 ekor benih yang bersaiz 2.5 cm adalah adalah 20 minit sahaja.
•Benih ikan gemar memakan moina terutama sekali ketika benih sedang membesar.
•Bungkah moina itu akan terapung.
•Benih akan mengerumuni dan memakan moina yang terpisah akibat pencairan moina beku.
•Masa yang diambil untuk memakan moina seberat 0.5 kg oleh 20,000 ekor benih yang bersaiz 2.5 cm adalah adalah 20 minit sahaja.
•Benih ikan gemar memakan moina terutama sekali ketika benih sedang membesar.
3.3 Artemia.
3.3.1 Penyediaan tangki penetasan.
•Bersihkan tangki penetasan menggunakan bahan pencuci.
• Masukkan air bersih sehingga ke paras yang ditetapkan.
•Masukkan garam kasar pada kadar 30 gram per 1 liter air.
•Kemasinan air adalah 30 ppt.
•Larutkan sehingga sekata.
•Berikan alat pengudaraan.
•Masukkan 1 gram sista artemia ke dalam 1 liter air.
•Biarkan selama 24 jam.
3.3.2 Penetasan Sista Artemia.
•Sista artemia akan menetas selepas 24 jam diram di dalam air masin.
•Sista artemia akan menetas sepenuhnya selepas 25 jam pada suhu 28˚C dan pH 7.5
•Jika pH rendah sista tidak akan menetas.
•Untuk atasi masalah ini bubuhkan sedikit soda bikarbonat untuk meninggikan pH air.
•Pastikan alat pengudaraan dipasang sehingga sista menetas.
•Sista artemia perlu terampai dan bergerak ke atas dan ke bawah oleh tindakan arus pengudaraan.
•Jika pengudaraan dihentikan sista akan mendak di dasar tangki dan mati.
•Sista artemia akan menetas selepas 24 jam diram di dalam air masin.
•Sista artemia akan menetas sepenuhnya selepas 25 jam pada suhu 28˚C dan pH 7.5
•Jika pH rendah sista tidak akan menetas.
•Untuk atasi masalah ini bubuhkan sedikit soda bikarbonat untuk meninggikan pH air.
•Pastikan alat pengudaraan dipasang sehingga sista menetas.
•Sista artemia perlu terampai dan bergerak ke atas dan ke bawah oleh tindakan arus pengudaraan.
•Jika pengudaraan dihentikan sista akan mendak di dasar tangki dan mati.
3.3.3 Kutipan hasil.
•Selepas 24 dieramkan sista akan menetas dan sedia untuk di makan oleh rega.
•Kutipan hasil dimulakan dengan mematikan alat pengudaraan dan biarkan selama 15 minit.
•Dalam tempuh 15 minit, sista artemia yang tidak menetas,kulit sista dan sista yang sambang akan terapung dipermukaan air.
•Artemia yang menetas akan mendak di dasar tangki.
•Untuk mempercepatan artemia mendak di dasar pastikan bahahian bawah tangki lutsinar.
•Cahaya yang menembusi bhg bawah tangki akan menarik perhatian artemia.
•Selepas 24 dieramkan sista akan menetas dan sedia untuk di makan oleh rega.
•Kutipan hasil dimulakan dengan mematikan alat pengudaraan dan biarkan selama 15 minit.
•Dalam tempuh 15 minit, sista artemia yang tidak menetas,kulit sista dan sista yang sambang akan terapung dipermukaan air.
•Artemia yang menetas akan mendak di dasar tangki.
•Untuk mempercepatan artemia mendak di dasar pastikan bahahian bawah tangki lutsinar.
•Cahaya yang menembusi bhg bawah tangki akan menarik perhatian artemia.
•Keadaan ini akan memudahkan artemia berkumpul di dasar.
•Apabila artemia telah berkumpul di dasar, buka paip di bhg bawah tangki dan tadah artemia dengan penapis halus.
•Kutipan hasil inin dilakukan sehingga semua artemia dikutip.
•Artemia yang telah dikutip dicuci untuk menghilangkan kemasinannya dan kemudian diberi kpeda rega yang berumur 5 hari.
•Artemia yang berlebihan boleh disimpan di dalam bekas yang mengandungi air berkemasinan 25 – 30 ppt selama 2 hari.
•Selepas tempoh ini artemia akan mati.
•Apabila artemia telah berkumpul di dasar, buka paip di bhg bawah tangki dan tadah artemia dengan penapis halus.
•Kutipan hasil inin dilakukan sehingga semua artemia dikutip.
•Artemia yang telah dikutip dicuci untuk menghilangkan kemasinannya dan kemudian diberi kpeda rega yang berumur 5 hari.
•Artemia yang berlebihan boleh disimpan di dalam bekas yang mengandungi air berkemasinan 25 – 30 ppt selama 2 hari.
•Selepas tempoh ini artemia akan mati.
4.0 Penyediaan Kastad Telur.
•Kastard telur biasanya digunakan sebagai makanan tambahan kepada rega udang dan ikan.
•Makanan ini biasanya diberi kepada rega yang berunur melebihi dari 10 hari.
•Digunakan apabila makanan hidup tidak ada atau terputus bekalan.
•Merupakan makanan yang seimbang dan mempercepatkan pertumbuhan anak benih.
•Penyediaan makanan ini adalah mudah dan murah berbanding dengan makanan hidup yang lain terutamanya artemia.
•Makanan ini juga boleh diperkaya dengan vitamin, mineral dan antibiotik untuk mengegah penyakit.
4.1 Bahan-bahannya.
a. Telur ayam - 2 biji
b. Isi Ikan Kayu/Kembung - 50 gram
c. Sotong Basah - 50 gram
d. Udang Basah - 50 gram
e. Susu tepung - 30 gram
f . Powder feed - 200 gram
g. Air - 1 liter
4.2 Caranya
a. Campurkan semua bahan a – g ke dalam alat pengisar ( blender ).
b. Kisar semua bahan sehingga hancur dan sekata.
Masukkan bancuhan tersebut dalam bekas dan
kukus selama 10 minit atau sehingga masak dan
sejukkan.
d. Kisarkan kastard tersebut menggunakan blender sehingga halus.
e. Letakkan kastard hancur tersebut di atas jaring
( sieve ) halus dan tekan sehingga keluar butiran halus.
f. Kumpulkan butiran ini ke dalam bekas sehingga semua kastard menjadi butiran halus.
g. Berikan kastard tersebut kepada rega yang di
asuh.
SEKIAN, TERIMA KASIH
a. Telur ayam - 2 biji
b. Isi Ikan Kayu/Kembung - 50 gram
c. Sotong Basah - 50 gram
d. Udang Basah - 50 gram
e. Susu tepung - 30 gram
f . Powder feed - 200 gram
g. Air - 1 liter
4.2 Caranya
a. Campurkan semua bahan a – g ke dalam alat pengisar ( blender ).
b. Kisar semua bahan sehingga hancur dan sekata.
Masukkan bancuhan tersebut dalam bekas dan
kukus selama 10 minit atau sehingga masak dan
sejukkan.
d. Kisarkan kastard tersebut menggunakan blender sehingga halus.
e. Letakkan kastard hancur tersebut di atas jaring
( sieve ) halus dan tekan sehingga keluar butiran halus.
f. Kumpulkan butiran ini ke dalam bekas sehingga semua kastard menjadi butiran halus.
g. Berikan kastard tersebut kepada rega yang di
asuh.
SEKIAN, TERIMA KASIH
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