The effect of ethanol extract of a macroalgae Laurencia snyderia on growth parameters and vibriosis resistance in shrimp Litopenaeus vannamei

Bacterial diseases have been reported to be the major limiting factor in shrimp production. The use of natural products such as antimicrobials has been reported as a solution to the problem. The crude extract of a red seaweed Laurencia snyderiae obtained from the Persian Gulf was evaluated for shrimp growth performance and to determine in vivo efficacy of this seaweed in the prevention of shrimp Vibriosis. The ethanol extract from L. snyderiae (EELS) that was fed to the Artemia instar I for their enrichment was found to be non toxic to them. Shrimp Litopenaeus vannamei juveniles were fed with these enriched Artemia at 0 mg mL-1 (Control group), 200 mg mL-1, 400 mg mL-1 and 600 mg mL-1 for 30 days. The results obtained showed a significant increase (p < /em>