New emerging viral disease on Giant Gourami (Osphronemus goramy Lac.) in Java, Indonesia

Abstract

This study investigates the role of pathogens in the disease outbreaks and mass mortality affecting giant gourami (Osphronemus goramy) populations from 2018 to 2020, leading to significant economic losses. Presumptive diagnoses, based on clinical symptoms and references, implicated two viruses: Tilapia Lake Virus (TiLV) and Infectious Spleen and Kidney Necrosis Virus (ISKNV). Samples from four Indonesian provinces (West Java, Central Java, East Java and Yogyakarta) were tested molecularly for these viruses. The results revealed widespread viral pathogen involvement, with ISKNV prevalence ranging from 20% to 100% and TiLV prevalence consistently at 100%. These findings strongly suggest that the outbreaks were primarily caused by TiLV and ISKNV infections, potentially with other co-infecting pathogens. Bacterial pathogens, notably Aeromonas spp., Mycobacterium spp., and Pseudomonas spp., may have exacerbated the disease. This research highlights the emergence of viral diseases as a significant threat to giant gourami populations in Java, Indonesia.