The project originated out of the development of an oral peptide delivery system carried out in the frame of the Fisheries and Aquaculture Research programme (FAR) of the European Community. The main objective of the present project is to develop an \\'in food\\' or dietary delivery form of the peptide GnRH. Such a product would provide the fish farmer with a non-invasive, practicaland less time consuming technique, which allows mass treatment of fish without the negative effects of individual handling and capture. The specific indications for GnRH-loaded feed pellets are the induction, advancement and sychronisation of spawning of fish. After valorisation using model species (rainbow trout, African catfish and common carp), the dietary delivery form will be valorised in the fis farm on other economical species. In addition the applicability of the developed technology for the \\'in food\\' delivery of other compounds is investigated.