Gempylovirus is a genus of viruses that primarily infects fish, particularly those in the Scombridae family, which includes species like tuna and mackerel. These viruses are known to cause diseases that can lead to significant economic losses in the fishing industry. The most notable member of this genus is Gempylovirus species, which can result in symptoms such as lesions and increased mortality rates in affected fish populations. Understanding and managing these viruses is crucial for maintaining healthy fish stocks and ensuring sustainable fishing practices.