Business trip report, Switzerland, Kučera

During the periods of January 5–18, 2025, and subsequently October 27 – November 7, 2025, I completed professional internships at the production company Local Fish!, located in Rafz, Switzerland. The second internship was carried out together with my colleague Laura Ostolaza Perez-Cruz. The main objective of both internships was to gain practical experience in the out-of-season propagation of Eurasian perch (Perca fluviatilis) within a recirculating aquaculture system (RAS). During the stays, I actively participated in sperm collection and quality assessment, egg collection from females, fertilization procedures, and the stocking of eggs for incubation and further rearing. The internships also included participation in the daily operation and maintenance of the RAS, including system monitoring, water quality control, feeding, and equipment upkeep. The experience significantly contributed to expanding my practical knowledge of fish reproduction under controlled conditions and the operation of modern recirculating systems. Both internships took place in a professional and supportive environment, allowing for a valuable connection between theoretical knowledge and hands-on aquaculture practice.