DAO prepress abstract   -  DOI: https://doi.org/10.3354/dao03814

ABSTRACT: The ectoparasite Amyloodinium ocellatum is a dinoflagellate causing severe morbidity and mortality in both brackish and marine warmwater aquaculture fishes worldwide. A. ocellatum has a triphasic life cycle based on a free-living flagellate (the dinospore), a parasitic stage (the trophont), and a resting and reproductive cyst (the tomont). Current chemical treatments have shown some efficacy in eliminating dinospores but fail to inactivate the tomonts. The efficacy of alternative treatments was evaluated in vitro through sporulation tests and the quantification of dinospore production and motility. Hydrogen peroxide and peracetic acid efficiently decreased dinospore production at low concentrations, but total inactivation of tomonts was only achieved with higher dosages. Tomont inactivation was also observed with disinfectants such as sodium hypochlorite and Virkon S. This work provided insights into effective and environmentally friendly alternatives for the elimination of resistant forms of the marine parasite A. ocellatum.