{{Short description|Genus of viruses}} {{Use dmy dates|date=April 2017}} {{italic title}} {{Virusbox | name = ''Okavirus'' | image = Roniviridae virion.jpg | image_caption = ''Roniviridae'' virion | image2 = Yellow head virus genome.png | image2_caption = Yellow head virus genome | image_alt = | taxon = Tipravirus | synonyms = | synonyms_ref = | subdivision_ranks = | subdivision = }}
'''''Okavirus''''' is a genus of enveloped positive-strand RNA viruses which infect crustaceans.<ref name="ICTVReport" /> Host organisms are mostly shrimp.<ref>{{cite journal |last1=Walker |first1=PJ |last2=Cowley |first2=JA |last3=Dong |first3=X |last4=Huang |first4=J |last5=Moody |first5=N |last6=Ziebuhr |first6=J |last7=ICTV Report Consortium |title=ICTV Virus Taxonomy Profile: ''Roniviridae''. |journal=The Journal of General Virology |date=January 2021 |volume=102 |issue=1 |doi=10.1099/jgv.0.001514 |pmid=33108263|pmc=8116784 |doi-access=free }}</ref> Viruses associated with the genus include: gill-associated virus (GAV) which causes reddening, biofouling with exoparasites, emaciation, and massive mortality; and yellow head virus (YHV) which causes yellow head, arrest of feeding, and massive mortality.<ref name="ICTVReport">{{cite web|title=ICTV Report Roniviridae|url=http://www.ictv.global/report/roniviridae}}</ref><ref name=ViralZone>{{cite web|title=Viral Zone|url=http://viralzone.expasy.org/all_by_species/290.html|publisher=ExPASy|access-date=15 June 2015}}</ref> The name is derived from the 'Oka' or lymphoid organ in which the viruses are commonly detected and in which pathology occurs during acute infections. Lymphoid organs are anatomical structures common to penaeid shrimp. There are three species in this genus.<ref name="ICTVReport" />
==Structure== Viruses in the genus ''Okavirus'' are enveloped, with bacilliform geometries, and helical symmetry. The diameter is around 20–30 nm.<ref name="ICTVReport" /><ref name="ViralZone" />
==Genome== Genomes are linear and non-segmented, around 26 kb in length.<ref name="ICTVReport" /><ref name="ViralZone" />
==Life cycle== Entry into the host cell is achieved by attachment to host receptors, which mediates endocytosis. Replication follows the positive stranded RNA virus replication model. Positive stranded RNA virus transcription is the method of transcription. Crustaceans and mostly prawns serve as the natural host. Transmission routes are ingestion.<ref name=ICTVReport/><ref name=ViralZone />
== Taxonomy == thumb|Phylogenetic tree of ''Ronviridae'' The genus contains one subgenus with three species. Species are listed by their scientific name and followed by the exemplar virus of the species:<ref>{{cite web|title=Virus Taxonomy: 2024 Release|url=https://ictv.global/taxonomy|publisher=International Committee on Taxonomy of Viruses|access-date=20 March 2025}}</ref>
* ''Tipravirus'' ** ''Okavirus branchiae'', Gill-associated virus ** ''Okavirus flavicapitis'', Yellow head virus ** ''Okavirus orientale'', Yellow head virus type 8 (also called Yellow head virus genotype 8 and Yellow head virus 8)
==References== {{Reflist|2}}
==External links== * [http://www.ictv.global/report/roniviridae '''ICTV Report:''' ''Roniviridae''] * [http://viralzone.expasy.org/all_by_species/290.html '''Viralzone''': Okavirus] {{Baltimore classification}}
{{Taxonbar|from=Q3775810|from2=Q7365724|from3=Q57751806|from4=Q57754796}}
Category:Roniviridae Category:Virus genera