Investigation of the possibility use of Zataria multiflora (Avishan-e Shirazi) essence in control of fungal contamination of cultured shrimp, Litopenaeus vannamei

This study was conducted to evaluate the possibility of replacing Z. multiflora instead of antibiotics and chemicals in shrimp aquaculture industry to protect the environment and prevention of microbial resistance. In vitro MIC of Z. multiflora essential oil against Candida albicans and Fusarium solani obtained 0.004% and 0.008% respectively, also MFC of Z. multiflora essential oil against C. albicans and F. solani was 0.004% and 0.04%, respectively. The results showed that 0.0002% dosage of Z. multiflora essential oil against total count of fungi in sea water (salinity 39±1ppt) can decrease growth of fungi after 6 h and 0.0004%, 0.0008% and 0.0016% dosages can decrease the total count of fungi in sea water. But very low dosage of Z. multiflora essential oil in shrimp Litopenaeus vannamei leads to mortality. Lethal dose of Z. multiflora essential oil in shrimp postlarvae, juvenile (2±0.2g) and adults (10-12 g) was 0.00050%, 0.00045% and 0.00035%, respectively. The results indicated that Z. multiflora have a significant anti-fungal effect but is toxic for L. vannamei. We recommend that Z. multiflora essential oil can be used in non-living environment, such as disinfecting tanks and equipments.