Argulus species (Family: Argulidae), more commonly known as fish lice, are members of a large group of branchiuran parasites that infest and cause disease in fish. The argulids are crustaceans and are related to crabs, lobsters, and shrimp. This 5-page fact sheet was written by Natalie Steckler and Roy P. E. Yanong, and published by the UF Department of Fisheries and Aquatic Sciences, November 2013.
http://edis.ifas.ufl.edu/fa184