Sergii Boryshpolets and Borys Dzyuba have visited (2. 3. - 15. 3. 2020) Instituto de Ciencia y Tecnología Animal, Universitat Politècnica de València (Spain) for collaboration with colleagues from group of Aquaculture and Biodiversity leading by Prof. Dr. Juan Asturiano. The visit was organized to perform mutual study in field of spermatology of cartilaginous fish (small-spotted catshark Scyliorhinus canicula and Mediterranean starry ray Raja asterias). During the stay the investigation of sperm motility by means of high-speed microscopy was performed and discussion of forthcoming publications and future scientific projects with participation of USB was conducted. We greatly appreciate our Spanish colleagues for fruitful and very friendly collaboration, and we are looking forward to future cooperation with them.