Nimaviridae

Nimaviridae is a family of viruses that primarily infect crustaceans, specifically shrimp. The family contains one genus, Whispovirus, which includes the species White spot syndrome virus (WSSV).

Taxonomy

The family Nimaviridae is classified under the order Unassigned and contains only one genus, Whispovirus. The genus Whispovirus includes the species White spot syndrome virus, which is the most well-known and studied member of this family.

Structure

Viruses in Nimaviridae are enveloped, with bacilliform and rod-shaped geometries. The size of these viruses is around 120-150 nm in diameter, and 250-380 nm in length. The genome is non-segmented, circular, and around 300 kb in length.

Life Cycle

Viral replication is nuclear. Entry into the host cell is achieved by attachment of the viral proteins to host receptors, which mediates endocytosis. Replication follows the DNA strand displacement model. DNA-templated transcription, with some alternative splicing mechanism is the method of transcription. The virus exits the host cell by nuclear pore export, and budding. Crustaceans serve as the natural host.

Pathology

The most significant disease associated with Nimaviridae is White Spot Disease (WSD), caused by the White spot syndrome virus. WSD is highly lethal and contagious, affecting a wide range of crustaceans, particularly shrimp. It is characterized by the presence of white spots on the exoskeleton of the infected crustaceans.

Prevention and Control

Prevention and control of diseases caused by Nimaviridae, particularly WSD, primarily involve good aquaculture practices, early detection, and prompt action. Vaccines are not currently available for these viruses.

See Also

• Virus
• Crustacean
• White spot syndrome virus
• Aquaculture