FHF-prosjekt 901146 - Kunstig lys og rensefisk: Parasitization is a big problem faced by fish farmers throughout the world. While chemical treatment is an option, a biological solution based on predation of the relevant parasite by cleaner fish is a more environmentally friendly solution and in many cases more cost effective. Salmon lice, Lepeophtheirus salmonis, are a particularly costly problem for penned salmon (see Costello, 2009).