Sphaerothecum destruens
Scientific classification edit
Class: Ichthyosporea
Order: Dermocystida
Family: incertae sedis
Genus: Sphaerothecum
S. destruens
Binomial name
Sphaerothecum destruens
Arkush et al., 2003

Sphaerothecum destruens (the rosette agent) is a parasite of fish.[1][2] 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.[3] The genus Sphaerothecum is closely related to the genera Dermocystidium and Rhinosporidium.[2]


  1. ^ M. A. Ragan; C. L. Goggin; R. J. Cawthorn; L. Cerenius; A. V. Jamieson; S. M. Plourde; T. G. Rand; K. Söderhäll & R. R. Gutell (October 1996). "A novel clade of protistan parasites near the animal-fungal divergence". Proceedings of the National Academy of Sciences. 93 (21): 11907–11912. Bibcode:1996PNAS...9311907R. doi:10.1073/pnas.93.21.11907. PMC 38157. PMID 8876236.
  2. ^ a b Kristen D. Arkush; Leonel Mendoza; Mark A. Adkison & Ronald P. Hedrick (2003). "Observations on the life stages of Sphaerothecum destruens n. g., n. sp., a mesomycetozoean fish pathogen formerly referred to as the rosette agent". Journal of Eukaryotic Microbiology. 50 (6): 430–438. doi:10.1111/j.1550-7408.2003.tb00269.x. PMID 14733435. S2CID 84692014.
  3. ^ "Deadly parasite could endanger salmon and trout populations in U.K." Science Daily. June 20, 2009.