Parasitic copepods are common on cultured and wild marine finfish (Johnson et al., 2004; Costello, 2009). Although several species have been recognised to have the potential to affect growth, fecundity, and survival of their hosts, it has only been with the development of semi-intensive and intensive aquaculture that their importance as disease-causing agents has become evident (Johnson et al., 2004). Members of the family Caligidae, referred to as sea lice, are the most commonly reported species on fish reared in brackish and marine waters. Sea lice have a significant economic impact due to reduced growth performance resulting from the presence of the sea lice and/or the residues of chemical treatments, as well as from the costs of the treatments themselves (Sinnott, 1999; Rae, 2002; Johnson et al., 2004). Indirect and direct losses due to sea lice in salmonid aquaculture globally are estimated to be around (sic)300 million annually (Costello, 2009). However, until now the economic impact in other marine non-salmonid culture has not been reported.