Joris Koene is a world leading expert on reproduction and sexual selection in hermaphroditic animals. Scientific achievements include providing an explanation for the bizarre dart shooting behaviour of land snails, uncovering the mechanism of sexual motivation in freshwater snails, and identifying the first accessory gland protein in the semen of a hermaphrodite. His research group works at the forefront of its field, combining innovative methods and techniques and maintaining the world’s longest-standing breeding facility for freshwater snails. His research integrates different biological levels (e.g., behaviour, evolution, ecology, physiology, neuro-endocrinology) and addresses both evolutionary and mechanistic aspects of hermaphroditism in animals, to ultimately obtain a comprehensive understanding of both why and how sexual selection affects simultaneous hermaphrodites. He also uses his knowledge about socially transferred materials, such as seminal fluids, and flexible reproduction in education and outreach activities that include bio-art and teaching innovation.