Largemouth Bass Virus

Also known as: Largemouth Bass Virus

Largemouth Bass Virus (LMBV) is a double-stranded DNA virus associated primarily with disease in largemouth bass (Micropterus salmoides). While the virus can be found in multiple freshwater fish species, it only causes significant mortality in largemouth bass. Discovered in 1991, LMBV has spread through much of the Eastern, Southern, and Midwestern United States but has not been observed in introduced bass populations in Oregon. Infected fish may exhibit few or no external symptoms, but the virus can cause large-scale die-offs, particularly during the warmer months. Transmission occurs through direct fish-to-fish contact or by consuming infected carcasses. LMBV does not pose a risk to humans, and infected fish are considered safe to eat.

Distribution: Central and Eastern USA
Hosts: Many species of freshwater fish, but mortalities in largemouth bass
Detection Methods: Cell culture – unspecified
Target Tissue: Internal organs (e.g., swim bladder, spleen)