Fish Culture. Consider the following issues in catfish culture:

Transcription

1 SW 419 July 2002 W I L D L I F E P R O J E C T INTRODUCTION Fish culture is an activity that involves a good deal of work, but it can offer a valuable learning experience and financial rewards as well. The term fish culture implies raising fish in a controlled situation where there is seldom enough natural food available for the number of fish involved. You can raise and feed large numbers of fish in a relatively small area. You can then harvest and market the fish. Fish Culture The success of your culture operation depends largely on the amount of effort you spend learning about the project before you actually begin. Good planning before you begin is as essential as good management techniques are during the project. The operation may vary in size from the use of a tank to the use of a raceway or pond. Regardless of the size of the project, manage it well and keep good records. I. CATFISH CULTURE Catfish production involves growing catfish in controlled bodies of water. They can be harvested, processed and sold through food stores; or sold to A typical catfish or trout tank. outflow fishermen who enjoy the sporting qualities of catfish as well as using them for food. Catfish can be grown in open ponds, cages, streams, raceways or tanks. Both white and blue catfish have been cultured, but more is known about culturing the channel catfish. Producing catfish involves two stages: (1) spawning brood fish for production of fry (baby fish 1 inch long or less) and growing these fry to fingerling size (1 to 10 inches); and (2) growing fingerlings to food fish size. Fish are stocked at high rates and, because of this, have to be fed artificially. Consider the following issues in catfish culture: A typical catfish or trout cage. 1. Chemical treatment of fingerlings for diseases and parasites before stocking. 2. Water quality (including oxygen, carbon dioxide, ammonia, other gases, minerals, hardness, silt, organic matter, pesticides and temperatures). 3. Methods of spawning (pond, pen, aquarium).

2 A typical catfish or trout raceway. 4. Methods of culture (cage, open pond, raceway, tank). 5. Diseases and parasites. 6. Construction of culture units (cage, pond, raceway, tank). 7. Renovating old ponds vs.building new ones. 8. Stocking rates (will vary with type of culture, quality and rate of water flow). 9. Harvesting methods (seining, draining, fish-out, etc.). 10. Feeding rates and kinds of feed (size of pellet, quality and amount of protein, and floating vs. sinking pellet). 11. Types of catfish markets (individual, fishermen, restaurants, supermarkets, processing plants, fish-out operators, fingerling producers). 12. Size of fingerlings to stock (will depend on what size fish the market wants, when they will be sold, length of growing season, etc.). 13. Mechanical feeding vs. hand feeding. THINGS TO DO 1. Review three or more of the references at the end of this section and learn all you can before starting this activity. Keep in mind the above 13 topics while reviewing. Your success in this activity will depend on how well you review these references. 2. Visit a catfish farm and discuss problems and solutions with manager. 3. Decide which type of culture you have facilities and money to operate. This could vary from a pond 1 /10 acre in size to a raceway. You may want to purchase or build a small tank or tub. 4. Determine what catfish feeds are available and the probable difference in growth per pound of feed. 5. After setting up the culture facility and filling it with water, purchase your fingerlings from a reputable dealer. Your county Extension agent should know some. 6. Visit with a local fish farmer, state fish hatchery, fishery biologist,or county Extension agent and learn methods of transporting fish. Select the best method for your transportation. 7. Learn to recognize common parasites of fish and how to treat them. 8. Keep good records throughout the growing season and prepare a financial report when the fish are sold. II. TROUT CULTURE This activity is limited to places where there is a year-round supply of water suitable for trout. Trout culture involves the production of trout or trout eggs. For some, trout culture is a sideline; for others, it is a main source of income. It requires intensive management for either purpose. Your culture operation may range from a large scale operation involving raceways on down to a small operation involving only a tub or small tank. It is important to remember is that regardless of the size of your operation, you must manage it well and keep good records. A trout culture enterprise can consist of one or more of four kinds of fish culture. These are: 1. Operating a fish-out pond. Small fingerling trout are stocked in a pond, fed pelleted feed until they grow to a catchable size, and fished by anglers for a fee. Some operators lease fishing privileges on an annual basis. 2. Rearing small fingerling trout to market-size fish. Fingerlings are grown in raceways or tanks until

3 they are about 8 to 14 inches long. Raceways generally are narrow, rectangular structures 80 to 100 feet long with flowing water 2 to 3 feet deep. Production ponds of other shapes have also been successful. One raceway usually spills into another in a series of two or more stairlike structures. The raceways can be excavated waterways or can be built of concrete or concrete block. Each must have water- control structures, preferably of concrete. If tanks are used they may be of any size. One possibility is to split a 55- gallon steel drum in half, making two tanks. Trout in the raceways or tanks are raised on a diet of dry pelleted feed. Trout food can be purchased at most food stores. It takes about 2 pounds of food to produce a 1-pound trout in 10 to 14 months at water temperatures of 50 to 70 F. If raised in water colder than 50 F, trout take two years or more to reach market size; in water warmer than 70 F, they grow slowly and are more subject to diseases. 3. Producing fingerling-sized trout. Eyed eggs are held until hatched in special trays (called Whitlock- Vibert boxes) of running water. Several days after hatching, the small fish, or fry, are transferred to rearing ponds, raceways or tanks where they grow to fingerling size: 1 to 6 inches. They may then be sold to other trout producers. 4. Producing eyed eggs. This requires rearing and holding adult trout in special ponds until the spawning season. The eggs are then stripped from the females and fertilized with sperm stripped from males. The eggs are called eyed eggs when the eyes of the developing trout become visible, usually within two or three weeks after fertilization. INCOME FROM TROUT You might earn income from one or more of the following trout-raising activities: 1. Operating a fish-out pond. People come to your pond to fish. They pay for their catch by the inch or pound and you restock as needed to provide successful fishing. 2. Selling fry, fingerlings or larger live fish for stocking trout farms, private ponds or other waters. 3. Selling freshly dressed fish to local markets or restaurants. In a large-scale operation, dressed trout are usually frozen-packed. Fresh fish from small trout farms may be sold to larger operators for packaging and marketing. Fish processing is closely regulated by state and federal laws, and the market often demands fish of a specific size. 4. Selling eyed eggs. Many farmers start the season s production with fertile eggs bought from a commercial fish breeder. Fish eggs can be airshipped in special containers to almost any part of the country. SUITABLE WATER Any successful trout culture operation requires a reliable, year-round flow of high-quality water from springs, wells or streams. The water source should be carefully studied. These standards must be met: 1. Temperature. Water between 50 and 65 F is ideal for best growth and greatest economic returns. Water of 46 to 55 F is the most suitable for hatching trout eggs. 2. Oxygen. Water must have at least five parts per million (ppm) of dissolved oxygen; seven ppm is the minimum where eggs are hatched.

4 3. Hardness. Hard water (50 to 250 ppm dissolved minerals or more) produces trout more economically than soft water; management problems are fewer. 4. Water must be free of harmful gases, minerals or other pollutants. 5. Diseases from wild fish in the water supply can also be a serious problem. The number of trout that can be raised each year is determined by the volume and quality of the water flowing through the raceways. Annual production from a well-managed operation having high-quality water is about 10,000 pounds for each cubic foot per second (cfs) 450 gallons per minute (gpm) of water flow in a temperature range of 50 to 65 F. Thus, a flow of five cfs (2,250 gpm) of good-quality water should produce 50,000 pounds of trout a year. These estimates are based on information from established trout farms where raceways are designed for at least one complete exchange of water per hour. In some raceways, two exchanges may be necessary. A trout farmer could successfully raise trout with less than one exchange of water per hour, but usually production is lower and chance of disease is higher. During the first or second season, an inexperienced operator would produce probably no more than 6,000 to 8,000 pounds of trout per cubic foot of water flow (450 gpm). WHERE YOU CAN GET HELP Seek the advice of trout-farming organizations and visit fish farmers and state or federal fish hatcheries in your area. Contact your state fish and wildlife agency for license requirements. You can also apply to your county Extension agent, state Fish and Wildlife Agency, and U.S. Soil Conservation Service for help in planning, constructing and financing certain phases of your trout culture activity. THINGS TO DO 1. Learn all you can before starting this activity. 2. If you have a potential water source for trout culture, have it checked by a state fishery biologist to determine if it will support trout. 3. If your water source is adequate, you may produce trout in a raceway, tank or pond. 4. Purchase fingerlings, eyed eggs or adult fish to get started. Get information on where to obtain them from your county Extension agent. 5. Keep accurate records of management procedures, costs and sales. III. BAIT MINNOW CULTURE Minnows are the favorite live bait of bass and crappie anglers. Where the demand for minnows is great and the supply short, 4-H ers can develop a profitable retail minnow business. Minnow producers will do especially well where there are numerous private ponds or a large impoundment or river nearby. The 4-H er whose family operates a large fee-fishing pond may want to build a minnow pond below the fish pond and market minnows on the spot. PONDS One or two minnow ponds will usually be enough to produce bait for local trade. Each pond should be one-tenth to one-quarter acre in size or larger, with a natural supply of water from a small spring or fish pond, provided the water is filtered to prevent the minnow pond from becoming infested with game fish or fish eggs. (Either a sand and gravel filter or a socklike filter made of saran mesh per square inch, No. 12 weave -- is appropriate. Ask your county Extension agent or state fishery biologist for advice on water filtration.) Enough water to keep the water level constant is needed. Water that must be supplied by pumping is expensive water. The pond should have straight sides, a smooth, level bottom and a narrow width so that minnows may be

5 harvested with seines or screens stretched across ponds. Ponds should be 4 to 5 feet deep at one end and about a foot deep at the other. The dam should be 7 feet wide at the top and built with a two-to-one slope. Build a wide spillway so rain water will not go over the dam. A clay core beneath the dam is often necessary to limit loss of water by seepage. Install a 4-inch drainpipe so that you can empty the pond. For a valve you can use a screw-in plug on the pipe end below the dam. Another drainage device consists of two metal pipes joined with an elbow. The pipe extends through the levee at the pond bottom, then to the surface of the water. A screen fitted over the top keeps fish from going through the pipe in either direction. By lowering the surface end of the pipe, you can regulate the water level. By laying the pipe flat on the bottom you can drain the pond. Grease the threads of the elbow with heavy grease to prevent rusting. Lay the pipe low enough so that all water will be drained. Be sure to poison the water with rotenone before stocking with minnows. If this is not done, other species of fish present in the pond will compete with minnows and reduce their production. STOCKING Common minnow species for commercial production are the golden shiner, goldfish and the fathead (blackhead or tuffy). Stock 15 to 20 pounds of golden shiners or 1,000 fathead minnows per surface acre. (Don t stock shiners in the pond if it is less than 1 /4 acre in size.) Buy your fish from a reliable producer who is known for selling disease-free stock. Stock minnows in your pond during a period recommended by your county Extension agent. In the Upper South, this period is approximately February 1 to March 15. Male fatheads often die after the spawning period, so don t be surprised if you see them floating on the surface after spawning in spring and throughout the summer. concrete blocks on the pond bottom or by anchoring wide boards along the sides of the ponds, placing them a foot below and parallel to the water surface. FEEDING AND MANAGEMENT Minnows feed on microscopic plant and animal life collectively called plankton. Fertilize minnow ponds eight to 10 times a year to keep water green with plankton. You can obtain information on fertilizing ponds from your county Extension agent. Fertilizing is never begun before the water warms to about 65 F. Fertilizer spread in cooler water promotes the growth of undesirable filamentous (pond scum) or blue-green algae. In order to supplement the minnows food supply, you should feed minnows a mixture consisting of 35 parts (by weight) soybean meal, 35 parts peanut cake, 15 parts fish meal and 15 parts distiller s dry solubles. Have the feed ground and pelleted in a nearby feed mill. You can also substitute a mixture of 50 parts (by weight) of hog supplement and 50 parts of poultry laying mash. Feed minnows up to 10 pounds of mixture per acre daily in warm weather. Somewhat lesser amounts should be fed in cold weather. Reduce feed when most of the minnows have reached market size. If minnows remain small with plentiful feed, remove half of them so that the others will grow. PRODUCTION From a 1-acre pond you should produce 400 to 900 pounds of golden shiner bait minnows annually. The production of fatheads in a one-tenth acre pond may reach 15,000 minnows or more. Production will depend upon management. Fatheads like to lay eggs on the underside of objects. You can provide nests for them by placing Freeboard is the vertical distance between the water surface and the dam top.

6 PESTS Crayfish will burrow in the ground near minnow ponds, causing seepage. To get rid of them, place 1 teaspoon of lye (sodium hydroxide) in each crayfish hole and crush in the mound. Lye is caustic and poisonous. Wear gloves when applying it. Keep it away from pets and children. One common type of minnow pond-drain system. HARVEST If the pond has been constructed properly, minnows can be trapped with minnow seines. You catch small numbers of fish by baiting with stale bread over an umbrella lift seine or by capturing in minnow traps. Occasionally you may wish to sell the entire crop of minnows at one time. You can catch them by draining the pond. To harvest minnows by draining, build a catch basin of concrete or boards when you construct your pond. Build the basin 10 feet square and 1 foot deep below the drainpipe openmg inside the pond if the pond will be one-third acre or smaller. When the pond is drained, most minnows will collect in the basin. Before harvesting your minnows, find a place to sell them. Try businesses such as sporting goods stores and bait shops. Find out which size they prefer, and harvest them when most of the minnows in your pond reach that size. Grade minnows into small, medium and large sizes. Large minnows should sell for a higher price than small minnows. The fathead is naturally small sized and is excellent for crappie fishing. The golden shiner often grows to a length of 6 inches. Large ones are good bass bait; small shiners make good crappie bait. Minnows too small for bait should be restocked and grown to market size. Fish-eating birds, such as herons and kingfishers, are hosts of parasites. Such birds are protected from hunters by law, but they ll probably avoid your minnow ponds if you burn rope firecrackers along the banks. Or you could stretch wires or cords across the pond and attach tinfoil strips to them. The calcium carbide sound-blast gun is also effective and inexpensive to operate. Muskrats will not tunnel through the bottom of a dam, but they will dig through a steep brace slope just below the water surface and make dens in the soil above normal water level. If muskrats are numerous, trap them. PARASITES You can avoid most diseases and parasites by stocking clean brood fish. In addition, you should give your brood fish a pre-pond drench. Mix 2 grams of potassium permanganate per 100 gallons water in a clean drum. (Let a pharmacist weigh this material for you.) Place minnows in this solution for one hour or until they show signs of stress (coming to top, turning on side, gasping, etc.). Put them immediately into fresh water-then release in the pond. Potassium permanganate may also be used in minnow ponds as a cleansing agent to reduce many diseases and parasites. Use 5.4 pounds potassium permanganate per acre-foot of water and drag in You can keep minnows in well-aerrated holding tanks or in wire baskets placed in natural running water for a day or so between harvest and sale. Caution: They may die if kept crowded for long periods. Also, use care in transferring minnows from one water temperature to another. Sudden temperature changes will kill them. It is best to temper them. This means to gradually change their water temperature by adding amounts of the warmer or colder water until the desired temperature is reached. This may take up to one hour before the final transfer to new water is made.

7 burlap bag over pond surface. Stir water immediately (with boat and motor or otherwise). Repeat treatment on third and sixth days for best results. The anchor parasite resembles a small white stick with a bulb attached at the end. The area is usually inflamed at the point where parasites are attached to the body of the fish. There is no completely effective control against anchor parasites. The above treatment may help reduce the parasite load, but the best prevention is to secure clean brood fish. Sometimes grubs black, yellow, or white are found inside fish. These parasites may be spread by fish-eating birds. Whenever possible, pick dead fish out and dispose of them. Aquatic insects, such as the back swimmer and water tiger, prey on minnows. Control them by spraying kerosene or diesel fuel over the pond surface at the rate of 2 to 4 gallons per acre. You should contact your county Extension agent for help in applying these chemicals. DISEASES Water mold is a fungus disease, similar to bread mold, which attacks the body of a fish. On fish in water it looks like a whitish patch, and it usually appears on injured or crowded minnows. It can be found on shiners in ponds with a low oxygen content. To control water mold, remove dead, diseased fish daily and treat entire pond with potassium permanganate crystals as described on above. Fin rot usually appears as a white margin on the outer edges of fins. In advanced cases, fin rays are left bare and frayed, and the entire fin may disappear. Disease is usually found in minnows crowded in tanks. Remove all dead minnows and those showing advance deterioration, in addition to reducing the number of minnows in tanks. THINGS TO DO 1. Determine the demand for minnows in your area. 2. Check with a local minnow producer, county Extension agent or state fishery biologist on pond requirements. 3. Build and stock one minnow pond. Keep a complete record of expenses and profits for one year. WORDS TO KNOW Brood fish: Adult fish used as a source of eggs and sperm for the production of fertile eggs and, therefore, young fish Fingerlings: A general term for immature fish of one to three inches in length (to about the length of your finger) and in their first year of life Fish culture: Rearing fish in a controlled situation using techniques to improve or increase yield usually for commercial purposes (includes supplemental feeding, disease control and water quality management) Fish-out: A harvesting operation in which fish are removed from a pond by angling (fishing) Fry: A general term for immature fish from hatching up to about 1 inch in length Parasite: An organism which lives in or on another organism, from which it takes its food Spawning: The reproduction process of fishes Water hardness: Refers to the dissolved mineral content of the water-particularly dissolved calcium and magnesium

8 ACKNOWLEDGEMENTS This material was originally prepared by the Southern Regional 4-H Wildlife Literature Committee through a grant from Atlantic Richfield Foundation. COMMITTEE: Alvin C. Blake, Tennessee; Dan T. Gardner, Alabama; Dennis Goodman, Kentucky; James E. Miller, Arkansas; Lewis R. Shelton, III, Mississippi; Andrew Weber, North Carolina (Vice Chairman); and James L. Byford, Tennessee (Chairman). SPECIAL ASSISTANTS: Rita Schrader, Ben Nottingham, Dale Powell. Some material in this guide was adapted from existing 4-H literature. Materials taken from: 4-H Wildlife, Fish Management, Agricultural Extension Service, the University of Tennessee, Knoxville, Tennessee, and Raising Minnows, Texas Agricultural Extension Service, Texas A&M University, College Station, Texas. The Clemson University Cooperative Extension Service offers its programs to people of all ages, regardless of race, color, sex, religion, national origin, disability, political beliefs, sexual orientation, marital or family status and is an equal opportunity employer. Clemson University Cooperating with U.S. Department of Agriculture, South Carolina Counties, Extension Service, Clemson, South Carolina. Issued in Furtherance of Cooperative Extension Work in Agriculture and Home Economics, Acts of May 8 and June 30, 1914 Public Service Activities