13 – Diet and Fish Husbandry

Publisher Summary This chapter discusses the culture methods, nutrient requirements, feed formulation, and feeding practices for several important commercial aquaculture species with diverse culture environments and technologies. These species include channel catfish, salmonids, tilapias, and penaeid shrimp. Farm-raised catfish are fed grain-based feeds, which give the fish a mild flavor, with the absence of a “fishy” odor. The flesh is mostly white muscle, which is free of intramuscular bones. There is considerable variation in feeding practices among commercial catfish farms. Some farmers feed a fixed amount of feed in the pond daily, whereas other farmers feed what the fish in each pond will efficiently consume each day, using a floating feed so feeding activity can be observed. Salmon and trout reared for market are raised in ponds, tanks, raceways, and net pens (cages). Transfer to sea cages must be done when the fish are undergoing smoltification and are able to osmoregulate in the marine environment. The salmonid fry are first fed a finely textured mash, and as they increase in size, the size of the feed particles increases. The small fry are fed almost constantly, and as their size increases, the feeding frequency decreases.