Aquatic feeds ( Fish Feeds )

The nutritional content of the feed depends on what species of fish is being cultured and at what life stage. When fish are reared in high-density indoor systems or confined in cages and cannot forage freely on natural food (e.g., algae, aquatic plants, aquatic invertebrates, etc.), they must be provided a complete diet. In contrast, supplemental (i.e., incomplete or partial) diets are intended only to help support the natural food normally available to fish in ponds or outdoor raceways. Supplemental diets do not contain a full complement of vitamins or minerals but are typically used to help fortify the naturally available diet with extra protein, carbohydrate, and/or lipids.
Commercial fish diets are manufactured as either extruded (floating or buoyant) or pressure-pelleted (sinking) feeds. Both floating and sinking feed can produce satisfactory growth, but some fish species prefer floating, others sinking.
Feed is available in a variety of sizes ranging from fine crumbles for small fish to large (1/2-inch or larger) pellets. The pellet size should be approximately 20-30 percent of the size of the fish’s mouth gape.