Aquaculture is a fast growing sector. However, during larviculture and fish husbandry, many bottlenecks stilloccur. Many problems concern nutritional factors and can be avoided by a clear understanding of the developmentof the gastrointestinal system of the various fish species. Parameters, such as enterocyte height, the presence of enterocyticsupranuclear vacuoles and ‘the point of no return’, can be used to monitor and prevent food deprivation.This information can also be used to compose a feeding regime with rotifers, Artemia en copepods.