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The family Hadakaviridae , including the genus Hadakavirus , accommodates capsidless viruses with a 10- or 11-segmented positive-sense (+) RNA genome. Currently known hosts are ascomycetous filamentous fungi. Although phylogenetically related to polymycovirids with a segmented double-stranded RNA genome and certain encapsidated picorna-like viruses, hadakavirids are distinct in their lack of a capsid ('hadaka' means naked in Japanese) and their consequent inability to be pelleted by conventional ultracentrifugation; they show ribonuclease susceptibility in host tissue homogenates. This is a summary of the International Committee on Taxonomy of Viruses (ICTV) Report on the family Hadakaviridae, which is available at ictv.global/report/hadakaviridae.

The Quadriviridae is a monogeneric family of non-enveloped spherical viruses with quadripartite dsRNA genomes, each segment of 3.5-5.0 kbp, comprising 16.8-17.1 kbp in total. The family includes the single species Rosellinia necatrix quadrivirus 1. All quadriviruses infect filamentous fungi, and have unique virion structures compared with other known dsRNA viruses. Pathogenicity has not been reported for these viruses. This is a summary of the ICTV Report on the taxonomy of family Quadriviridae, which is available at http://www.ictv.global/report/quadriviridae.

The Partitiviridae is a family of small, isometric, non-enveloped viruses with bisegmented double-stranded (ds) RNA genomes of 3-4.8 kbp. The two genome segments are individually encapsidated. The family has five genera, with characteristic hosts for members of each genus: either plants or fungi for genera Alphapartitivirus and Betapartitivirus, fungi for genus Gammapartitivirus, plants for genus Deltapartitivirus and protozoa for genus Cryspovirus. Partitiviruses are transmitted intracellularly via seeds (plants), oocysts (protozoa) or hyphal anastomosis, cell division and sporogenesis (fungi); there are no known natural vectors. This is a summary of the International Committee on Taxonomy of Viruses (ICTV) Report on the taxonomy of the Partitiviridae, which is available at www.ictv.global/report/partitiviridae.