''Invertebrate iridescent virus 31'' (IIV-31), also known informally as isopod iridovirus, is a species of invertebrate iridescent virus in the genus ''

Iridovirus ''Iridovirus'' is a genus of viruses in the family '' Iridoviridae''. Insects serve as natural hosts. Currently, only two species are placed in this genus. ''Invertebrate iridescent virus 6'' (IIV-6) was recognised as the type species until su ...

''.

Oniscidea A woodlouse (plural woodlice) is an Isopoda, isopod crustacean from the Polyphyly, polyphyleticThe current consensus is that Oniscidea is actually triphyletic suborder Oniscidea within the order Isopoda. They get their name from often being ...

(commonly known by a variety of names including ''woodlouse'', ''pillbug'', ''slater'', ''rolly-polly'', ''potato bug'', et al.) serve as hosts. Infection is associated with decreased responsiveness in the host, increased mortality, and most strikingly, the emergence of an iridescent blue or bluish-purple colour due to the reflection of light off a

paracrystalline In materials science, paracrystalline materials are defined as having short- and medium-range ordering in their lattice (similar to the liquid crystal phases) but lacking crystal-like long-range ordering at least in one direction. Origin and ...

arrangement of virions within the tissues.

Taxonomy

In earlier centuries, blue individuals of otherwise drab oniscidean species had been discovered. They were sometimes interpreted to be new subspecies and were described as such: ''

Ligidium hypnorum ''Ligidium hypnorum'' is a species of woodlouse found across Europe and western Asia. It is a fast-moving, active species whichthat rarely grows longer than . accessed through the Natural Environment Research Council, NERC Open Access Research A ...

coeruleum'' Lereboullet 1843 and ''L. hypnorum amethystinum'' Schöbl 1861 (in reference to

cerulean Cerulean (), also spelled caerulean, is a shade of blue ranging between azure and a darker sky blue. The first recorded use of ''cerulean'' as a colour name in English was in 1590. The word is derived from the Latin word '' caeruleus'', "da ...

and amethyst, respectively). In 1980, the first research was published showing that the phenomenon of blue oniscideans is in fact a disease caused by an

iridovirus ''Iridovirus'' is a genus of viruses in the family '' Iridoviridae''. Insects serve as natural hosts. Currently, only two species are placed in this genus. ''Invertebrate iridescent virus 6'' (IIV-6) was recognised as the type species until su ...

. The aforementioned 'subspecies' have since been reinterpreted, not as distinct taxonomic entities, but as historical findings of individuals infected with this isopod iridovirus. In 2014, the 220-

kilobase A base pair (bp) is a fundamental unit of double-stranded nucleic acids consisting of two nucleobases bound to each other by hydrogen bonds. They form the building blocks of the DNA double helix and contribute to the folded structure of both DN ...

genome sequence of this virus was published. Then in 2018 (as part of the 2018b

taxonomy Taxonomy is the practice and science of categorization or classification. A taxonomy (or taxonomical classification) is a scheme of classification, especially a hierarchical classification, in which things are organized into groups or types. ...

release), it was formally accepted as a species by the

International Committee on Taxonomy of Viruses The International Committee on Taxonomy of Viruses (ICTV) authorizes and organizes the taxonomic classification of and the nomenclatures for viruses. The ICTV has developed a universal taxonomic scheme for viruses, and thus has the means to ap ...

, named ''Invertebrate iridescent virus 31'', and placed in the genus ''Iridovirus'' alongside the mosquito-hosted species ''Invertebrate iridescent virus 6.

Host range

IIV-31 infects members of the suborder Oniscidea. In particular, it has been reported in the scientific literature from the following families and species: *

Armadillidiidae Armadillidiidae is a family of woodlice, a terrestrial crustacean group in the order Isopoda. Unlike members of some other woodlice families, members of this family can roll into a ball, an ability they share with the outwardly similar but unr ...

(''Armadillidium vulgare'', ''A. decorum'') *

Cylisticidae Cylisticidae is a family of woodlice in the order Isopoda. There are at least 4 genera and more than 60 described species in Cylisticidae. Genera These four genera belong to the family Cylisticidae: * '' Cylisticus'' Schnitzler, 1853 (53 specie ...

(''

Cylisticus convexus ''Cylisticus convexus'', the curly woodlouse, is a species of woodlouse A woodlouse (plural woodlice) is an isopod crustacean from the polyphyleticThe current consensus is that Oniscidea is actually triphyletic suborder Oniscidea withi ...

'') *

Ligiidae Ligiidae is a family (biology), family of woodlouse, woodlice, the only family in the infraorder Diplocheta. Its members are common on rocky shores, in similar habitats to those inhabited by species of the bristletail ''Petrobius'' and the crab ...

(''Ligidium hypnorum'', ''L. koreanum'') *

Oniscidae Oniscidae is a family of woodlice, including the common woodlouse '' Oniscus asellus''. Six genera Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hie ...

(''

Oniscus asellus ''Oniscus asellus'', the common woodlouse, is one of the largest and most common species of woodlouse in the British Isles and Western and Northern Europe, growing to lengths of 16 mm and widths of 6 mm. Distribution The common woodlou ...

'') * Philosciidae (''Burmoniscus kathmandia'', ''Philoscia affinis'', '' P. muscorum'') * Platyarthridae ('' Niambia capensis'') *

Porcellionidae Porcellionidae is a terrestrial family of the order Isopoda. This family contains 530 species, found on every continent except Antarctica. The ventral plate of the thoracic exoskeleton flare out slightly over the legs. This "flare" is called t ...

('' Porcellio dilatatus'', '' P. laevis'', '' P. siculoccidentalis'', '' P. spinicornis'', ''P. scaber'', '' Porcellionides pruinosus'') * Trachelipodidae ('' Trachelipus rathkii'') *

Trichoniscidae Trichoniscidae are a family of isopods (woodlice), including the most abundant British woodlouse, '' Trichoniscus pusillus''. Most species of woodlice that have returned to an aquatic or amphibian way of life belong to this family. Several speci ...

(''

Androniscus dentiger ''Androniscus dentiger'', the rosy woodlouse or pink woodlouse is a species of woodlouse found from the British Isles to North Africa. Description ''A. dentiger'' is a small woodlouse, at only 6 mm (¼ in) long, and is characteristica ...

'', '' Haplophthalmus danicus'', ''H. mengii'', '' Hyloniscus riparius'', ''Trichoniscoides albidus'', ''T. helveticus'', ''Trichoniscus panormidensis'', '' T. pusillus'')

Geographic range

This virus has a wide geographic distribution. In particular, it has been reported in the scientific literature from: * Asia (Japan, Turkey) * Europe (former

Czechoslovakia , rue, Чеськословеньско, , yi, טשעכאסלאוואקיי, , common_name = Czechoslovakia , life_span = 1918–19391945–1992 , p1 = Austria-Hungary , image_p1 ...

, France, Italy, the Netherlands, Russia, United Kingdom) * North America (United States) * Oceania (Australia)

Tentative fossil

Early Cretaceous Myanmar amber isopod-09

An oniscidean fossilised in Early

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of th ...

Burmese amber Burmese amber, also known as Burmite or Kachin amber, is amber from the Hukawng Valley in northern Myanmar. The amber is dated to around 100 million years ago, during the latest Albian to earliest Cenomanian ages of the mid-Cretaceous period. The ...

was found that features iridescent blue patches. George Poinar Jr., an entomologist and

palaeontologist Paleontology (), also spelled palaeontology or palæontology, is the scientific study of life that existed prior to, and sometimes including, the start of the Holocene epoch (roughly 11,700 years before present). It includes the study of fossi ...

studying this fossil, tentatively suggested that the colouration may represent an ancient case of IIV-31.

References

External links

iNaturalist
– citizen science observations of ''Invertebrate iridescent virus 31'' {{Taxonbar, from=Q85769842 Iridoviridae