Sphaerothecum destruens

{{short description|Species of parasite of fish}}

{{Speciesbox

| image =

| image_alt =

| image_caption =

| status =

| status_system =

| status_ref = {{citation needed|date=}}

| genus = Sphaerothecum

| species = destruens

| authority = Arkush et al., 2003

| synonyms =

| synonyms_ref = {{citation needed|date=}}

}}

Sphaerothecum destruens (the rosette agent) is a parasite of fish.{{cite journal |author= M. A. Ragan |author2= C. L. Goggin |author3= R. J. Cawthorn|author4= L. Cerenius |author5= A. V. Jamieson|author6= S. M. Plourde |author7= T. G. Rand|author8= K. Söderhäll |author9= R. R. Gutell |name-list-style= amp |title=A novel clade of protistan parasites near the animal-fungal divergence |journal=Proceedings of the National Academy of Sciences |volume=93 |issue=21 |pages=11907–11912 |date=October 1996 |pmid=8876236 |pmc=38157 |doi= 10.1073/pnas.93.21.11907|bibcode= 1996PNAS...9311907R |doi-access= free }}{{cite journal |author=Kristen D. Arkush |author2=Leonel Mendoza |author3=Mark A. Adkison |author4=Ronald P. Hedrick |name-list-style=amp |title=Observations on the life stages of Sphaerothecum destruens n. g., n. sp., a mesomycetozoean fish pathogen formerly referred to as the rosette agent |journal=Journal of Eukaryotic Microbiology |volume=50 |issue=6 |pages=430–438 |year=2003 |pmid=14733435 |doi= 10.1111/j.1550-7408.2003.tb00269.x|s2cid=84692014 }} It was first discovered in the United States in association with invasive species including topmouth gudgeon, but was found to be the causative agent of a disease in the UK affecting salmonid species such as Atlantic salmon and brown trout. It is thought to pose more of a risk in Europe than in the US, as native species there are more susceptible to the parasite. The disease causes high rates of morbidity and mortality in a number of different salmonid species and can also infect other UK freshwater fish such as bream, carp, and roach.{{cite news |url=https://www.sciencedaily.com/releases/2009/06/090617155011.htm |title=Deadly parasite could endanger salmon and trout populations in U.K. |publisher=Science Daily |date=June 20, 2009}} The genus Sphaerothecum is closely related to the genera Dermocystidium and Rhinosporidium.