Feed Types
Commercial fish diets are manufactured as either extruded
(floating or buoyant) or pressure-pelleted (sinking) feeds.
Both floating or sinking feed can produce satisfactory
growth, but some fish species prefer floating, others sinking.
Shrimp, for example, will not accept a floating feed,
but most fish species can be trained to accept a floating pellet.
Extruded feeds are more expensive due to the higher manufacturing
costs. Usually, it is advantageous to feed a floating
(extruded) feed, because the farmer can directly
observe the feeding intensity of his fish and adjust feeding
rates accordingly. Determining whether feeding rates are
too low or too high is important in maximizing fish growth
and feed use efficiency.
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% of the size
of the fish species mouth gape. Feeding too small a pellet
results in inefficient feeding because more energy is used in
finding and eating more pellets. Conversely, pellets that
are too large will depress feeding and, in the extreme, cause
choking. Select the largest sized feed the fish will actively
eat.