INTRODUCTION Commercial catfish farming is an important agricultural industry in the United States, although Florida has lagged behind other southeastern states. More than 100,000 acres of water are currently used to pro- duce around 225 million pounds of catfish yearly in the United States. Of this market, about 275,000 pounds of food-sized fish were raised on 88 acres in Florida during 1981. The low commercial production of catfish in Florida, compared with other southeastern states, is primarily the result of marketing and environmental con- straints. A lack of adequate processing facilities for farm- raised fish and soils that are not suited for large, con- ventional embankment ponds have impeded development of the catfish aquaculture industry in the state. Nonetheless, catfish farmers are increasing their endeavors in Florida and prospects for future develop- ment of the industry may be promising. This publication addresses the basic techniques and procedures used in culturing catfish and is intended to be a general guide for the farmer who is contemplating raising catfish in Florida on a commercial basis. Catfish farmers often specialize either in producing food-sized fish for processing and marketing to wholesale and retail outlets, or in spawning and rearing fry and fingerlings for stocking to grow-out ponds and other aquatic systems (e.g., raceways and cages). Before building facilities and attempting to raise cat- fish, one must become thoroughly familiar with marketing potential, investment costs, and environmen- tal constraints that apply to a given area. Prices of farm- raised catfish for consumption are currently non- competitive with wild-caught fish in Florida. Moreover, consumers in the state seem to have a preference for "shorts" or sharpiess," i.e., fish of a relatively small- sized dressed carcass (2-5 ounces). Farmers who may be considering production of food fish should investigate marketing outlets for their product well before construct- ing facilities and stocking fish. Likewise, anyone intend- ing to produce fingerlings for sale as seed stock should be sure that they will be able to sell and transport their fish successfully. Producers must make a preliminary assessment of expected economic expenditures and returns to determine the potential profitability of catfish farming. The greatest capital outlays will be land, pond construction, equipment, and supplies. Major operating costs are feed, fingerlings (for rearing as food fish), labor, fuel, electricity, chemicals, and processing or transpor- tation costs. A marketing analyst should be consulted for assistance in estimating economic investments and prof- its. Environmental constraints such as the feasibility of pond construction, and water quality and quantity must be carefully considered when planning a fish farm and making an economic analysis. Several unique features of Florida's topography, climate, and aquatic systems show promising avenues for development of the catfish farming industry. Construc- tion of appropriate ponds for culturing catfish may be severely limited by soil types and topography throughout much of the state except in parts of the panhandle. However, there may be good potential for rearing fish by nontraditional methods such as in raceways or in cages placed in canals, borrow pits, or other suitable bodies of water. Because of the warm climate and long growing season, Florida farmers could possibly supply fingerlings or fresh food fish to markets in other states out-of-season or on a year-round basis. Cultivation of yellow bullheads (Ictalurus natalis), brown bullheads (I. nebulosus), white catfish (I. catus), or other species could provide alter- natives to rearing channel catfish (I. punctatus). Some of these species might be suitable for supplementing cur- rent consumer markets, and they may be more amenable to culture under certain conditions than are channel cat- fish. However, culture techniques are best known for channel catfish, and the methods and procedures outlined here are those that apply principally to channel catfish unless otherwise noted. FINGERLING PRODUCTION Brood Stock Management Selection of Brood Stock Successful fingerling producers select high quality brood fish and maintain them in good health to obtain maximum yields of offspring. Many catfish producers prefer to buy mature fish rather than waiting for finger- lings to reach spawning age. The best source of brood fish is a reputable hatchery. However, be careful not to buy culls, or fish that have been discarded because they have undesirable traits. Fish-farming trade magazines usually carry advertisements for brood stock available through established producers and growers. It is advisable to inspect brood fish closely before buying to ensure that healthy fish are obtained. Avoid purchasing fish recently taken from the wild, since they are often unreliable spawners and their finger- lings may grow more slowly and be less resistant to diseases than fingerlings from established hatchery stocks.