The largemouth bass (Micropterus salmoides) is a member of the sunfish family, Centrarchidae. Members of the genus (Micropterus) are known as black bass and share the sunfish family with the bream (Lepomis spp.), crappies (Pomoxis spp.) and several other genera.
The largemouth bass is native to the midwestern and southeastern United States and northeastern Mexico. At present, largemouth bass have been introduced throughout the United States and many other countries worldwide. Interest in the commercial culture of largemouth bass is due to the great demand and a high selling price compared to other cultured species.
The largemouth bass is one of the most popular sport fish in the United States. Although there has been extensive research on largemouth bass for many years, this work has almost exclusively addressed hatchery production and fisheries management.
Amazingly little research has been conducted on growth of bass to larger sizes, their nutritional requirements, or suitability as an aquaculture species. In the 1960s, Dr. Snow at Auburn University conducted a series of studies on raising largemouth to sizes of 6-8 inches on feed as a method of increasing and intensifying hatchery production for sportfish stocking.
During the 1980s a number of federal and state hatcheries refined feed training techniques, again to maximize hatchery production. In recent years aquaculturist have become interested in the culture of feed trained largemouth to larger sizes.
This interest is based on an increasing demand for large bass for remedial stocking in sportfish ponds, their use in commercial "trophy" lakes, and a demand for live bass as a food fish among ethnic Asians.
The production of largemouth bass fry follows well establish procedures dating back to the 1930s. Largemouth bass are usually pond spawned and do not require hormone or photoperiod manipulations. Broodfish of greater than or equal to 2 years of age and 1.5 pounds in weight are stocked into 0.5-1 acre spawning ponds at 50 brood pair per acre. Ponds must be free of existing fish.
Spawning ponds are normally not fertilized so that spawning behavior, eggs, and fry can be observed easily and more easily harvested. Broods may be stocked when temperatures reach 65°F and spawning should begin soon after.
Since spawning ponds are not fertilized a nursery pond should be prepared as soon as spawning begins using organic and inorganic fertilization so as to contain large numbers of food items (zooplankton) for the bass fry. When large numbers of fry can be seen in the spawning pond, fry should be transferred from the spawning to the nursery pond and stocked at 40,000 - 80,000 fry per acre.
After 3-4 weeks in a properly prepared nursery pond bass should reach 1.5-2.0 inches in length and be ready for feed 29 training.
To feed train largemouth bass (and several other species) the basic concept is to remove the fish from the natural source of food, crowd them at high densities, and present them with highly palatable prepared foods at frequent and regular intervals. For feed training, fingerlings (1.5-2.0 inch) are seined from the nursery pond, graded to uniform sizes, and stocked in flow through tanks (round or rectangular) at a high density, which is based on water flow.
Fish are then offered either freeze dried krill, ground fish flesh, or fish eggs. Freeze dried krill is especially effective, commercially available, and easy to feed and store. These highly palatable products are then gradually mixed in with a high quality salmonid diet.
With fish flesh and eggs a semi-moist diet is produced. Over a series of about a week, each day’s feed ration should be increasingly comprised of the manufactured feed. By Day 7 the fish should be consuming straight feed. Fish that have trained to take the feed will by this time be thick bodied, with large bellies, and can be removed with graders.
The "feed trained" fish should be moved to a separate tank or compartment and maintained on feed for several more days before pond stocking. Fish that haven’t obviously trained can be left in the tank and the use of moist training diets or krill may be repeated.
After an additional week most of these fish should adapt to the diet. With good results about 80-90% of the fish originally stocked should train to accept artificial diets. Recent studies have shown that offspring from second or third generation feed-trained fish train easier than those from forage fed fish indicating improvements from domestication.
