Efficacy of marine green alga Ulva fasciata extract on the management of shrimp bacterial diseases

Abstract

Secondary metabolites of the green algae, Ulva fasciata, were tested to determine the efficacy of controlling shrimp bacterial pathogens. Exploratory experiments indicated that an intermediate dose (1 g kg -1 of shrimp) of Ulva in the diet was highly effective at controlling bacterial pathogens of shrimp, as compared to lower (500 mg kg -1 ) and higher (1.5 g kg -1 ) doses. The pilot experiments evaluated the percent of relative protection afforded shrimps treated with Ulva diet and faced with various concentrations of bacterial pathogen. The survival of shrimps treated with Ulva diet was significant (P < 0.01). The present findings indicate that the green U. fasciata may be an excellent source for developing a potent medicated feed for shrimp disease management.