Abstract
This study aims to evaluate the resistance of six Indonesian tilapia strains to TiLV disease and assess the impact of mimicked daily water temperature fluctuations on the disease severity. Six widely cultured Indonesian tilapia (Oreochromis niloticus) strains were evaluatedfor resistance to tilapia lake virus disease (TiLVD). Resistance to TiLVD was assessed using two artificial infection methods, cohabitation and intraperitoneal (IP) injection. Fish infected with TiLVD exhibited behavioural, clinical and mortality patterns associated with TiLV disease.Virus presence was also confirmed molecularly. All six tilapia strains were susceptible to TiLV infection, causing disease and mortality. The range of mortality for cohabitation was 1.67% - 28.33% and for IP injection was 16.67% - 61.67%. The most resistant tilapia strain to TiLVdisease was Gesit, followed by Best, Red/Albino, Nirwana, Non-specific and Srikandi. Daily temperature variation results in higher significant virus-induced mortality pattern among tilapia strains. These findings can be used to guide the selection of appropriate tilapia strain andtemperature control to mitigate the adverse effects of TiLV associated disease.