Abstract The teleost digestive tract is simple and comprises the following parts: oropharyngeal cavity, oesophagus, stomach, intestine, rectum and anus. These organs are involved in the breakdown of ingested food macromolecules into small absorbable micromolecules. These small molecules are necessary for the maintenance, growth and energy needs of the body (Johnson, 1994; Junqueira and Carneiro, 2005). Besides processing food, some parts of the tract have evolved into organs of respiration (p...