Managing Enterocytozoon hepatopenaei (EHP), microsporidial infections in vannamei shrimp farming: An Advisory
The Indian aquaculture production has considerably improved during the last five years, especially after the introduction of the exotic Pacific white shrimp. Availability of imported specific pathogen free (SPF) broodstock provided the much needed growth rate to India’s brackishwater aquaculture sector. However, the intensification of vannamei farming has exacerbated the epizootics and disease issues are becoming a major constraint affecting productions and profitability. Among the listed viruses of the farmed crustaceans, the white spot syndrome virus (WSSV) and infectious hypodermal hemotopoetic necrosis virus (IHHNV) have been frequently reported from Indian subcontinent and, both these pathogens can be considered as endemic in India. Other viral pathogens such as infectious myonecrosis virus (IMNV), Taura syndrome virus (TSV), yellow head virus (YHV) which have been responsible for causing losses to aquaculture in the Americas and the Southeast Asian countries have so far not been scientifically confirmed from India. During the last couple of years, a number of disease syndromes such as running mortality syndrome (RMS), white faeces syndrome (WFS)/ white gut syndrome and growth retardation have been negatively impacting shrimp aquaculture in India. In the Southeast Asian countries, emergence of a new microsporidian parasite “Enterocytozoon hepatopenaei (EHP)” has been reported since 2009. Studies conducted at CIBA during the last one year also indicated widespread occurrence of EHP in Indian shrimp farming systems. Considering its reported association with growth retardation resulting in reduced farm productivity, this advisory has been brought out for the benefit of shrimp farming community to prevent production losses