Seaweed extracts as a natural control against the monogenean ectoparasite, Neobenedenia sp., infecting farmed barramundi (Lates calcarifer)

► Innovative natural treatments can manage ectoparasites in aquaculture. ► Seaweed extracts inhibit and delay embryo development and reduce hatching success. ► Asparagopsis taxiformis reduced hatching success from 99% to 3%. ► Asparagopsis taxiformis and Ulva sp. significantly delayed embryo development. ► Seaweed culture can be integrated into aquaculture systems to supply natural treatments.