Siphoviridae was a family of double-stranded DNA viruses in the order Caudovirales. The family Siphoviridae and order Caudoviraleshave now been abolished, with the term siphovirus now used to refer to the morphology of viruses in this former family. Bacteria and archaea serve as natural hosts. There was 1,166 species in this former family, assigned to 366 genera and 22 subfamilies. The characteristic structural features of this family are a nonenveloped head and noncontractile tail.
Myoviridae was a family of bacteriophages in the order Caudovirales. The family Myoviridae and order Caudovirales have now been abolished, with the term myovirus now used to refer to the morphology of viruses in this former family. Bacteria and archaea serve as natural hosts. There were 625 species in this family, assigned to eight subfamilies and 217 genera.
Podoviridae was a family of bacteriophage in the order Caudovirales often associated with T-7 like phages. The family and order Caudoviraleshave now been abolished, with the term podovirus now used to refer to the morphology of viruses in this former family. There were 130 species in this family, assigned to 3 subfamilies and 52 genera. This family was characterized by having very short, noncontractile tails. Many former phages in the former family Podoviriade are now classified in the Autographiviridae
Fiersviridae is a family of positive-strand RNA viruses which infect prokaryotes. Bacteria serve as the natural host. They are small viruses with linear, positive-sense, single-stranded RNA genomes that encode four proteins. All phages of this family require bacterial pili to attach to and infect cells. The family has 185 genera, most discovered by metagenomics. In 2020, the family was renamed from Leviviridae to its current name.
Tectiviridae is a family of viruses with 10 species in five genera. Bacteria serve as natural hosts. Tectiviruses have no head-tail structure, but are capable of producing tail-like tubes of ~ 60×10 nm upon adsorption or after chloroform treatment. The name is derived from Latin tectus.
Corticovirus is a genus of viruses in the family Corticoviridae. Corticoviruses are bacteriophages; that is, their natural hosts are bacteria. The genus contains two species. The name is derived from Latin cortex, corticis. However, prophages closely related to PM2 are abundant in the genomes of aquatic bacteria, suggesting that the ecological importance of corticoviruses might be underestimated. Bacteriophage PM2 was first described in 1968 after isolation from seawater sampled from the coast of Chile.
Plasmaviridae is a family of bacteria-infecting viruses. Acholeplasma species serve as natural hosts. There is one genus in the family, Plasmavirus, which contains one species: Acholeplasma virus L2. All viruses known in this family have been isolated from species in the class Mollicutes.
Fuselloviridae is a family of viruses. Sulfolobus species, specifically shibatae, solfataricus, and islandicus, serve as natural hosts. There are two genera and nine species in the family. The Fuselloviridae are ubiquitous in high-temperature (≥70 °C), acidic hot springs around the world.
Guttaviridae is a family of viruses. Archaea serve as natural hosts. There are two genera in this family, containing one species each. The name is derived from the Latin gutta, meaning 'droplet'.
Globuloviridae is a family of hyperthermophilic archaeal viruses. Crenarchaea of the genera Pyrobaculum and Thermoproteus serve as natural hosts. There are four species in this family, assigned to a single genus, Alphaglobulovirus.
Picovirinae is a subfamily of viruses in the order Caudovirales, in the family Salasmaviridae. Bacteria serve as natural hosts. There are two genera and seven species in this subfamily.
Bottigliavirus is the only genus in the family Ampullaviridae and contains 3 species. Ampullaviridae infect archaea of the genus Acidianus. The name of the family and genus is derived from the Latin word for bottle, ampulla, due to the virions having the shape of a bottle. The family was first described during an investigation of the microbial flora of hot springs in Italy.
Proboscivirus is a genus of viruses in the order Herpesvirales, in the family Herpesviridae, in the subfamily Betaherpesvirinae. Elephants serve as natural hosts. EEHV1 is apathogenic for African elephants but causes fatal haemorrhagic disease in Asian elephants. The name "Proboscivirus" comes from the Greek word προβοσκίς or "proboscis" meaning "the elephant trunk," for which the virus accordingly uses as its means of contraction and transmission to enter the elephant's body.
Schizotequatrovirus is a unassigned genus of viruses in the unassigned family Straboviridae, in the class Caudoviricetes,. Bacteria serve as natural hosts. There are three species in this genus.
Tequatrovirus is a genus of viruses in subfamily Tevenvirinae of family Straboviridae. Gram-negative bacteria serve as the natural host, with transmission achieved through passive diffusion. There are 84 species in this genus.
Peduoviridae is a family of viruses in the class Caudoviricetes. It was previously treated as a subfamily of the morphology based family Myoviridae, which has been found to be paraphyletic and is no longer recognised. Bacteria serve as natural hosts. There are 126 species in this subfamily, assigned to 58 genera.
Spounavirinae is a subfamily of viruses in the order Caudovirales, in the family Herelleviridae. Bacteria serve as natural hosts. There are currently five species in this subfamily, divided among 2 genera.
Myohalovirus is a genus of viruses in the order Caudovirales, in the family Myoviridae. Bacteria and archaea serve as natural hosts. There are three species in this genus.
Spbetavirus is a genus of viruses in the order Caudovirales, in the family Siphoviridae. Bacteria serve as natural hosts. There is only one species in this genus: Bacillus virus SPbeta.
Tristromaviridae is a family of viruses. Archaea of the genera Thermoproteus and Pyrobaculum serve as natural hosts. Tristromaviridae is the sole family in the order Primavirales. There are two genera and three species in the family.
