Family: Chuviridae

Genus: Piscichuvirus

Distinguishing features

Piscichuviruses are primarily distinguished from viruses of other genera in the family based on nucleic acid sequence and organization differences (Di Paola et al., 2022). Members of the genus Piscichuvirus have L protein sequences that are >31% identical to each other.

Genome organization and replication

Piscichuviruses have nonsegmented linear genomes of 9.9–11.3 kb with three ORFs encoding a glycoprotein (GP), a large (L) protein with an RNA-directed RNA polymerase (RdRP) domain, a nucleoprotein (NP), and/or a protein of unknown function (Shi et al., 2016, Argenta et al., 2020, Costa et al., 2023). The replication cycle of piscichuviruses remains to be elucidated.

Biology

Piscichuviruses have been associated with decapod crustaceans, atheriniform and syngnathiform fish, and squamate reptiles as follows:

• Guǎngdōng red-banded snake chuvirus-like virus (GRSCV) has been associated with red-banded snakes (colubrid Lycodon rufozonatus (Cantor, 1842)) in China (Shi et al., 2016);
• hardyhead chuvirus (HhCV) has been associated with fly-specked hardyheads (atherinid Craterocephalus stercusmuscarum (Günther, 1867)) in Australia (Costa et al., 2023);
• Herr Frank virus 1 (HFrV1) has been associated with boa constrictors (boid Boa constrictor Linnaeus, 1758) in Brazil (Argenta et al., 2020);
• Sānxiá atyid shrimp virus 4 (SxASC4) has been associated with unspecified shrimp (Atyidae) in China (Shi et al., 2016); and
• Wēnlǐng fish chu-like virus (WFClV) has been associated with longspine snipefish (macroramphosid Macroramphosus scolopax (Linnaeus, 1758)) in China (Shi et al., 2016).

Unclassified piscichuviruses have been associated with blenniiform fish in Australia and freshwater and marine turtles in the USA (Laovechprasit et al., 2023).

Species demarcation criteria

Members of different species have amino-acid identities of complete L sequences of <90% (Di Paola et al., 2022).

Related, unclassified viruses

Virus names and virus abbreviations are not official ICTV designations.