Document Type



Virginia Institute of Marine Science

VIMS Department/Program

Marine Advisory Program (MAP)

Publication Date



Fishery Resource Grant FRG 2010- 12


A substantial high-value market exists for wild-caught live summer flounder (Paralichthys dentatus). An important component of accessing this market is the ability to hold wild-caught flounder in land based recirculating aquaculture systems (RAS). A major constraint to holding summer flounder in land-based RAS is fish mortalities associated with the ectoparasite argulus spp. Very little information exists that provides a live flounder holding facility with FDA approved treatment options to prevent introduction of argulus from wild caught fish into holding systems. The project objective was to test the available FDA approved chemotherapeutics for treatment of ectoparasite infections in summer flounder. To validate treatment efficacy, 8 infected individuals were treated with bath treatments according to maximum recommended doses (250ppm formalin for 60 m; 200 ppm hydrogen peroxide for 30 m; and freshwater for 20 m) and then transferred to separate RAS to monitor for two weeks. Daily observations were made to determine if treatments were lethal to the attached argulus. Following the two week monitoring period, fish from all treatments showed no sign of a reduction in attached argulus. According to the findings of this study, there are currently no FDA approved treatments for argulus infections on summer flounder. It is recommended that a live wild flounder holding facility visually inspect all incoming fish for the presence of argulus and maintain fish in a quarantine system prior to holding in a RAS.


Flounder, argulus, mortality