Salmon (a large fish with a golden red color) is a type of cold water fish and belongs to the sub-group of salmon. This fish has a wide rainbow stripe on each side of the body. Today, rainbow trout has become the number one fish of most cold water fish breeding workshops in most parts of the world.

One of the features that has drawn attention to this fish is its adaptability to dense breeding conditions. On the other hand, this fish is not very strict in choosing food and has a good growth rate. For the food of this fish, usually, a type of aquatic food is used that remains floating on the water, which is called extrude. The name of this type of fish feed is the device with which it is produced, which is known as an extruder brand.