Marnaviridae
Marnaviridae is a family of positive-stranded RNA viruses in the order "Picornavirales". The first species of this family that was isolated is "Heterosigma akashiwo RNA virus" (HaRNAV) in the genus "Marnavirus", that infects the toxic bloom-forming Raphidophyte alga, "Heterosigma akashiwo". Using a sequence-based framework an additional twenty marine RNA viruses have been added to the family. HaRNAV was isolated from water collected in the Strait of Georgia in British Columbia, Canada, from a concentrated virus assemblage using the host "Heterosigma akashiwo" (NEPCC 522). It must not be confused with two other unrelated viruses that infect this  host, "Heterosigma akashiwo virus 01" (HaV-1, isolate: HaV53) in the genus "Raphidovirus", and "Heterosigma akashiwo Nuclear Inclusion Virus" (HaNIV). Taxonomy. The family contains the following seven genera: Structure. Virions in "Marnaviridae" are non-enveloped, with icosahedral geometries, and T=pseudo3 symmetry. The diameter is around 25 nm. Genomes are linear and non-segmented (monopartit), around 8.6 kb in length. The capsid consists of three major capsid proteins (MCPs: VP1, VP2, VP3), each having a Jelly roll fold and a minor capsid protein (mCP) that is located around the five-fold axes on the inside of the capsid. Life cycle . Entry into the host cell is achieved by penetration into the host cell. Replication follows the positive stranded RNA virus replication model. Positive stranded RNA virus transcription is the method of transcription. The virus exits the host cell by tubule-guided viral movement. Marine phytoplankton serve as the natural hosts of the only known member of the family "Marnaviridae".